# can high levels of co2 be a BAD thing? (not talking fish)



## zavikan (Jan 5, 2009)

ok...the tank.

38 Gal
EI Ferts
2.5 WPG from 96 watt coralife 6700k 8hr photoperiod
Flourite substrate
pressurized co2 via Rex Reactor
2217 Eheim
Weekly 50% water change
Moderately to heavily planted


I read something someplace about keeping co2/ferts/light balanced, and that an excess of any will cause problems. I was of the mind that co2 *always* should be kept at the max possible (before the fish start to act wierd/sluggish/gasp).

Am I incorrect? will high co2 combined with relatively lean ferts/light timers CAUSE algae?


For instance. I have BBA completely covering my driftwood, yet all my plants grow beautifully and algae free. 1 piece of driftwood is dead inline to the filter output. another is in a lower flow zone.

WHAT GIVES?!


----------



## DarkCobra (Jun 22, 2004)

zavikan said:


> I read something someplace about keeping co2/ferts/light balanced, and that an excess of any will cause problems. I was of the mind that co2 *always* should be kept at the max possible (before the fish start to act wierd/sluggish/gasp).


Everything I've read and experienced suggests this is correct.



zavikan said:


> Am I incorrect? will high co2 combined with relatively lean ferts/light timers CAUSE algae?


Some people report profuse BBA growth on the plastic of filter outputs where CO2 is injected. Does this mean excess CO2, in combination with other factors and on certain surfaces, can cause BBA? I don't know, but the important thing is that there is no algae on the plants. I would not trade less algae on plastic/driftwood for more algae on plants!



zavikan said:


> For instance. I have BBA completely covering my driftwood, yet all my plants grow beautifully and algae free. 1 piece of driftwood is dead inline to the filter output. another is in a lower flow zone.


Driftwood is notorious for that.

Every month or two, I put a little hydrogen peroxide in a spray bottle and take my driftwood out of the tank. I spray the wood every few minutes until I think the algae is mostly dead, rinse it, then return it to the tank.


----------



## jmhart (Mar 14, 2008)

zavikan said:


> I read something someplace about keeping co2/ferts/light balanced, and that an excess of any will cause problems. I was of the mind that co2 *always* should be kept at the max possible (before the fish start to act wierd/sluggish/gasp).
> 
> Am I incorrect? will high co2 combined with relatively lean ferts/light timers CAUSE algae?







DarkCobra said:


> Everything I've read and experienced suggests this is correct.


Not trying to sound contradictory, but...


Everything _I've _read and experienced suggest this is not correct.

Everyone talks about balance, but I think that confuses people into thinking there is a magic formula. There's not. Your tank needs enough nutrients, and enough light, and enough co2. 

If you dose one of the prescribed methods of dosing, like EI, PPS, or PMDD, your tank has enough nutrients. That eliminates one of the variables. From there all you've got to worry about are light and co2. If you've got livestock(which in your case you don't) then you have an upper limit on how much co2 you can pump into the tank. That means you also have an upper limit on how much light should be over the tank. However, no livestock means no co2 limit, which means no light limit...to some degree. At some point, no matter how much co2 you have, you can have enough light that you still have algae.

For example, I've run a tank without fish, dosing EI with AS as substrate, and jacked my co2 way up (50-60 ppm) and used 6wpg over a 17g tank. No algae, great growth. But, the moment I let that co2 drop...algae city.

However, in my experience, not enough nutrients combined with enough light and enough co2 does result in algae issues.


----------



## BrentD (Dec 11, 2008)

If you get enough CO2 in the water that it starts to fizz, you've got too much. Keep in mind that CO2+water = Carbonic acid. So too much CO2 will drop your Ph.


----------



## jmhart (Mar 14, 2008)

BrentD said:


> If you get enough CO2 in the water that it starts to fizz, you've got too much. Keep in mind that CO2+water = Carbonic acid. So too much CO2 will drop your Ph.


_Any _amount of co2 drops pH. That's how pH controllers and drop checkers measure co2.


----------



## DarkCobra (Jun 22, 2004)

jmhart said:


> Not trying to sound contradictory, but...
> 
> Everything _I've _read and experienced suggest this is not correct.


Maybe there was a misunderstanding. I was confirming the original poster's statement that CO2 is best kept near the maximum allowable amount.



jmhart said:


> Everyone talks about balance, but I think that confuses people into thinking there is a magic formula. There's not. Your tank needs enough nutrients, and enough light, and enough co2.


I agree it's confusing. Unlike excess light or nutrients, excess CO2 is beneficial up to the point where it harms fish/plants. CO2 therefore doesn't fit the literal meaning of "balance", yet everyone refers to it as part of the balance, hopefully with the understanding of that caveat.


----------



## jmhart (Mar 14, 2008)

DarkCobra said:


> Maybe there was a misunderstanding. I was confirming the original poster's statement that CO2 is best kept near the maximum allowable amount.


Yep, I misunderstood. The OP kind of made two contradicting statments: excess of any will cause algae AND co2 should be kept high., and you said "yes, that's true". I was confused on which one you were saying is true.

Anyway, point is, we agree, co2 should be kept as high as possible(considering livestock of course)


----------



## elihanover (May 15, 2008)

I think he's (she's?) asking if excess CO2 can cause algae? If the OP is not, then I am.


----------



## BrentD (Dec 11, 2008)

jmhart said:


> _Any _amount of co2 drops pH. That's how pH controllers and drop checkers measure co2.


True. I meant too much will drop your pH drastically.


----------



## jmhart (Mar 14, 2008)

elihanover said:


> I think he's (she's?) asking if excess CO2 can cause algae? If the OP is not, then I am.



Too much co2 will not cause algae.


Too much light, or too little nutrients will. Too many nutrients with too little co2 will also cause algae. 

But, too much co2 will not.


----------



## jmhart (Mar 14, 2008)

BrentD said:


> True. I meant too much will drop your pH drastically.


Within reasonable limits, this isn't bad for plants. What I mean by reasonable is that at some point, it's likely that the environment will be too acidic for plants, but in the hobby I've never, nor have I heard about anyone, reached that level. I've had tanks with pH below 5 and plants were fine. 

In regards to livestock, absolutely too much co2 is an issue, but 

A) pH drop due to co2 is not harmful to fish...too much co2, which causes a pH drop is, but the pH drop itself is not the culprit

B)the OP is talking about a fishless tank.


To the OP:

What are you using to measure co2?


----------



## MarkMc (Apr 27, 2007)

jmhart said:


> Within reasonable limits, this isn't bad for plants. What I mean by reasonable is that at some point, it's likely that the environment will be too acidic for plants, but in the hobby I've never, nor have I heard about anyone, reached that level. I've had tanks with pH below 5 and plants were fine.
> 
> In regards to livestock, absolutely too much co2 is an issue, but
> 
> ...


Is it possible to make the water too acidic by injecting CO2? There must be some point that you can't dissolve any more CO2 into an amount of water at a particular temperature. I wonder what that saturation level is and what would the resulting pH be. My guess is that those levels would not cause issues with aquatic plants only.


----------



## BrentD (Dec 11, 2008)

jmhart said:


> Within reasonable limits, this isn't bad for plants. What I mean by reasonable is that at some point, it's likely that the environment will be too acidic for plants, but in the hobby I've never, nor have I heard about anyone, reached that level. I've had tanks with pH below 5 and plants were fine.
> 
> In regards to livestock, absolutely too much co2 is an issue, but
> 
> ...


But would aquatic plants grow in a tank full of Perier? (I'm legitimately asking. My gut instinct says no, but if I'm wrong than that seems like it would be really interesting to see. Would definitely bring pearling to a whole new level.)


----------



## gogreen (Sep 18, 2008)

funny cause i was gonna ask this same question tonight. i guess as a follow up...how much or how do you measure fertilizers when you deciede to pump up the co2 to the reasonable maximum level?


----------



## jmhart (Mar 14, 2008)

BrentD said:


> But would aquatic plants grow in a tank full of Perier? (I'm legitimately asking. My gut instinct says no, but if I'm wrong than that seems like it would be really interesting to see. Would definitely bring pearling to a whole new level.)



I guess that would fall under my "reasonable limits" clause. I've never gotten to that point, and I've dropped pH below 5.0 with co2 without issue.

Perrier has a pH of 5.46, TDS of 475...so, I'd say it's safe to say that at that level you'll have fizzy water. 

However, I still don't think that's an issue, because it's just a pH thing (and partial pressure of the gas) and plants can live below that pH.


----------



## jmhart (Mar 14, 2008)

gogreen said:


> funny cause i was gonna ask this same question tonight. i guess as a follow up...how much or how do you measure fertilizers when you deciede to pump up the co2 to the reasonable maximum level?


Well, there's not just one answer to that. There are several schools of thought.

Personally I use EI and PPS, which are both fertilization methods that ensure there are enough nutrients in the water at all times. EI adds enough nutrients so that plants have an abundant supply over the course of a week, and PPS adds just enough so that plants have an abundant supply over a single day. For more information google EI or PPS (PPS-Pro).

Basically, through years of study, on the hobby level and scientifically, we've all come to a set of parameters that seem to be pretty good food plants. By parameters, I mean the amount of nutrients in the water. The established dosing methods make it easy to reach those parameters.


----------



## zavikan (Jan 5, 2009)

You know, I never thought of that.... Hows THAT for co2 injection? inline perier bottle! :icon_bigg

I guess you guys have answered the question....

it still doesnt explain the algae issue....:icon_conf


----------



## jmhart (Mar 14, 2008)

zavikan said:


> You know, I never thought of that.... Hows THAT for co2 injection? inline perier bottle! :icon_bigg
> 
> I guess you guys have answered the question....
> 
> it still doesnt explain the algae issue....:icon_conf


How are you measuring co2 in your tank?


----------



## zavikan (Jan 5, 2009)

cheap plastic 2 piece drop checker... cant find it online. was red sea or some other crap.

Using a 4.5 DKH solution. my PH test solution is around 1.5-2 yrs old (could this be false reading for me?)

I put it in blue, by the end of the day its green, by the next morning its yellow (even though I shut my co2 off at night)


----------



## DarkCobra (Jun 22, 2004)

zavikan said:


> I guess you guys have answered the question....
> 
> it still doesnt explain the algae issue....:icon_conf


Consider this. Why do our deliberate choices of light/nutrients/CO2 eliminate algae?

It's not because we're starving it. Everything the algae needs to grow is available in abundance.

It's not because we're poisoning it. Crank up the lights and watch the algae grow, even though the chemical enviroment is the same.

It's because we're depriving the algae its growth trigger - an unbalanced environment. Without that trigger, algae stops reproducing, shuts itself down, and dies.

Now ask yourself why algae is growing only on the driftwood, and all the driftwood in your tank, seemingly regardless of water current and amount of light.

Something in the driftwood is acting as a growth trigger.

It may be possible to tweak your tank to cancel out that growth trigger on the driftwood. But I expect it would take either extremely fine control that would be hard to maintain. Or perhaps a more drastic change that would limit plant growth, and/or encourage algae growth elsewhere.

So, in my opinion, your realistic options are:

1) Leave the algae on the driftwood and learn to love it.
2) Clean the driftwood periodically.
3) Eliminate the driftwood.
4) Dry the driftwood, seal it with penetrating epoxy, and weigh it down.


----------



## MarkMc (Apr 27, 2007)

DarkCobra said:


> It's because we're depriving the algae its growth trigger - an unbalanced environment. Without that trigger, algae stops reproducing, shuts itself down, and dies.


Wouldn't you say that the higher plant life in the tank is a factor also? By this model if you had a tank with no plants, lights, CO2 and balanced ferts that algae would not grow-only when the equation is "unbalanced" would it grow. I think it's dependent on the relationship/competition with higher plants. That it's not just the algae but also the plants negative response to an unbalanced environment.


----------



## DarkCobra (Jun 22, 2004)

MarkMc said:


> Wouldn't you say that the higher plant life in the tank is a factor also? By this model if you had a tank with no plants, lights, CO2 and balanced ferts that algae would not grow-only when the equation is "unbalanced" would it grow. I think it's dependent on the relationship/competition with higher plants.


I don't use the "competition" model because I can't find any significant way plants compete with algae.

The plants aren't starving the algae. In EI and similar dosing protocols, all nutrients are present in adequate, if not abundant, amounts. Algae can grow just fine in much leaner conditions.

The plants probably aren't poisoning the algae. That concept is called allelopathy, and though a lot of people believed in that years ago when I first entered this hobby, I hardly see it mentioned anymore except for disputing it.

The plants do compete mechanically - healthy plants grow faster, preventing algae access to light; and get trimmed more often, reducing algae accumulation. But this alone isn't enough in my opinion to support a "competition" model, because speed of plant growth does not always inversely correlate to speed of algae growth; there can be huge disparities.

There has to be another factor, and every other factor I know of fits better into an "algae growth trigger" model, like unbalanced conditions.

Organic chemicals from waste and decay are also likely a growth trigger. Healthy plants can absorb and utilize them. Unhealthy plants, fish waste, and uneaten food produce them. Consider a piece of driftwood as a big chunk of dead plant which is slowly decaying, and it's no wonder it tends to grow algae.

Now about your hypothetical plantless balanced tank. Assuming it also contains no animals, this model indeed predicts little increase in algae growth. Some would be due to greater access to light, lack of trimming, and lack of algae eaters; possibly some more due to buildup of organic waste released from bacteria.

I would be interested if someone actually tried this. But even if this model fails on an empty tank, I would still prefer it because it works better than any other model I've seen on a _planted_ tank.


----------



## plantbrain (Dec 15, 2003)

jmhart said:


> Well, there's not just one answer to that. There are several schools of thought.
> 
> Personally I use EI and PPS, which are both fertilization methods that ensure there are enough nutrients in the water at all times. EI adds enough nutrients so that plants have an abundant supply over the course of a week, and PPS adds just enough so that plants have an abundant supply over a single day. For more information google EI or PPS (PPS-Pro).
> 
> Basically, through years of study, on the hobby level and scientifically, we've all come to a set of parameters that seem to be pretty good food plants. By parameters, I mean the amount of nutrients in the water. The established dosing methods make it easy to reach those parameters.


No, EI adds enough for 2-3 days worth basically, the residual level is the key, plants adapt to residual concentrations enzymatically.

That's why they grow easily at higher levels and still grow fairly well at lower concentrations.

If you want really low daily dosing, EI can be divided into daily type dosing and a more stable lower residual can be maintained. This is still much higher than PMDD or it's cousin PPS, but the method can be adjusted to suit a daily dosing, EI was and is never meant to be dosed just once a week.

I know I've never stated that anywhere.

Regards, 
Tom Barr


----------



## plantbrain (Dec 15, 2003)

jmhart said:


> Not trying to sound contradictory, but...
> 
> If you dose one of the prescribed methods of dosing, like EI, PPS, or PMDD, your tank has enough nutrients. That eliminates one of the variables.


But only EI actually eliminates, as far a test, the nutrient variables.
It provides non limiting nutrients as far as growth is concerned.

The other 2 involve limitations for many aquariums, PO4 mostly and Fe.

So they are *dependent*.

If the plant is strongly or even moderately limited by PO4, this affects CO2 demand, which both in turn reduce rates of growth.

This is why some see better results with leaner dosing, whereas others do not.

Their test and conclusions have dependency on other factors which they attribute to "less is better". This has long been a criticism of mine about PMDD and it's cousin PPS. PPS adds a bit more PO4 to the dosing, but is not much different, rehashed and reworded PMDD.

If you chose a non limiting nutrient control for hydroponics, since Ed of PPS(likes to fancy himself as Hydroponics guy, would you chose a really lean reference that has some limitations? 

Or would you chose say a modified Hoagland's solution that is the reference standard? Hoagland's is very rich and it is used foliarly as well for fertigation without issues for aquatic nurseries(Tropica(Den), Pisces(Aust), FAN(USA) etc)

That and DI water, or perhaps a salt solution if interested in salinity stresses as a serve limiting solution.

All other results would fall in between these two ranges, an upper bound and lower bound. Now you can say something about the results.

EI is based on this same approach but uses NO3, not NH4 and is about 1/5th the strength of Hoaglands. Paul Kromboltz and Gerloff in 1966 used a similar formula for studying uptake in their research and found similar results. So I found similar results unbeknownst at the time that are independent and concur with the research and logic.

Some of PMDD also drew strongly from this paper, but fear and algae had them using more conservative dosing, as is the case for many still today.
I know the folks that developed PMDD.

Ruling out nutrients independent of CO2 or light is not hard or an issue Liebig of Gerloff have not been fully aware off, nor has the concept eluded me. It seems to still elude many however even when the basic logic and information is out there for all the read and see. Aquarist cannot suggest a CO2 or a nutrient level is adequate without a comparative light reading, nor a non limiting broadly applied CO2 levels without also addressing nutrients independently.

http://www.new.aslo.org/lo/toc/vol_11/issue_4/0529.pdf

That's science, references, real meat and taters.

As far as CO2, I think there is an upper bound for CO2, I honestly do not know what it is, but likely far far beyond that of the practical, 200+ ppm[aq] or more, maybe much more.

regards, 
Tom Barr


----------



## zavikan (Jan 5, 2009)

wow... I'm not even going to pretend I understood all of that... but I 'think' I got the intent behind it...Unfortunately confusing me more.


Stability in the tank seems to be crucial. I am lazy. This is a bad combo. That being said, I have also automized every aspect of tank life except for feedings/water changes/trimming/cleaning. My Peristaltic pumps run 7 day timers, so they alternate just like the EI dosing regime. (also needed this b/c my pumps push out a whopping 66ml a minute dose! thats alot to dilute.. Didnt want to try and dose daily)

Automatic Day:

9:00AM EI fert dose via peristaltic pump into rex reactor
11:30AM co2 turns on
Noon Lights turn on
7:45 co2 turns off
8:00pm lights turn off


If keeping the drop checker in the yellow w/ 4.5 dkh eliminates co2 as a variable...

and EI dosing eliminates ferts as a variable (which is what I think I got out of your postings Tom)

well heck, I know my lamp is indeed a 96 watt 6700k 2.5 wpg set up.

Thus, all variables eliminated?

All of my plants grow well, except for slow growers... java fern/anubias
YET, I get algae on slow growers to the point of unsightliness and plant removal.

My driftwood requires constant weekly attention.


----------



## jmhart (Mar 14, 2008)

plantbrain said:


> ...EI was and is never meant to be dosed just once a week.
> 
> I know I've never stated that anywhere.
> 
> ...


When I typed it, I knew it was going to be confused. I didn't go into detail since it wasn't the purpose of this thread, but my summary of EI should been that it's designed factoring nutrient requirements over a week. I hoped that, for anybody that didn't know, they'd google it to find out full information, rather than simply take what I wrote and say "Oh, i just dump it in all at one since jmhart said so."


----------



## DarkCobra (Jun 22, 2004)

zavikan said:


> wow... I'm not even going to pretend I understood all of that... but I 'think' I got the intent behind it...Unfortunately confusing me more.


I read Tom's post simply as "limitation of any required nutrient limits plant growth". 



zavikan said:


> All of my plants grow well, except for slow growers... java fern/anubias
> YET, I get algae on slow growers to the point of unsightliness and plant removal.
> 
> My driftwood requires constant weekly attention.


This changes my assessment.

You originally said _all_ your plants grow algae-free. And even for driftwood, weekly cleanings are excessive.

I would say you have an imbalance.



zavikan said:


> and EI dosing eliminates ferts as a variable (which is what I think I got out of your postings Tom)


I hate to open this can of worms, but...

My opinion is that EI does NOT eliminate ferts as a variable. It provides a reasonable guess. But it doesn't take into account actual absorption rates of nutrients. More importantly, it doesn't account for other sources of nutrients.

I just looked at your tank, and it appears you have fluorite substrate. So in combination with EI, you have two significant sources of iron. Several posts I've seen here suggest excessive iron contributes to BBA outbreaks, and that reducing iron fixes the problem.

Might be worth a try.


----------



## jmhart (Mar 14, 2008)

DarkCobra said:


> I hate to open this can of worms, but...
> 
> My opinion is that EI does NOT eliminate ferts as a variable. It provides a reasonable guess. But it doesn't take into account actual absorption rates of nutrients. More importantly, it doesn't account for other sources of nutrients.
> 
> ...


Yes, that is definitely a can of worms.

EI does take into account absorption rates to a certain degree; the idea is that it over estimates the absorption rates...hence the large water change at the end of the week to reset the tank.

Also, since Flourite is a baked clay substrate, I do not think that the iron is bio available. However, I could definitely be wrong on this. Seachem advertises the amount of iron in it, but I'm not sure that's really the benefit of flourite. The CEC is the benefit.


----------



## JDowns (Mar 6, 2008)

DarkCobra said:


> My opinion is that EI does NOT eliminate ferts as a variable. It provides a reasonable guess. But it doesn't take into account actual absorption rates of nutrients. More importantly, it doesn't account for other sources of nutrients.


I think you should re-read the EI article, you may find much of what you are stating is based on either myth or not fully reading the basis of EI.

*A Typical Tank* 
A typical routine for a *high light* tank with *low fish load*:
Volume 80 liters (20 gal high standard tank)
5.5 watts/ gal. - two 55watt 5000K/8800K lamps
CO2-25-30ppm (I turn my CO2 off at night)
Canister filter
Fluorite (any porous iron rich material will do) about 7-10cm depth


----------



## fishscale (May 29, 2007)

Can someone please try growing plants in 10 gallons of Perrier?


----------



## plantbrain (Dec 15, 2003)

zavikan said:


> wow... I'm not even going to pretend I understood all of that... but I 'think' I got the intent behind it...Unfortunately confusing me more.
> 
> 
> Stability in the tank seems to be crucial. I am lazy. This is a bad combo. That being said, I have also automized every aspect of tank life except for feedings/water changes/trimming/cleaning. My Peristaltic pumps run 7 day timers, so they alternate just like the EI dosing regime. (also needed this b/c my pumps push out a whopping 66ml a minute dose! thats alot to dilute.. Didnt want to try and dose daily)
> ...


I'd sugegst workign more on raisung that pesky light up higher, say another 4-6" higher if possible, or swaping it for a pair of T5 39W spread out over a wider area, and running one bulb for 6 hours and then the other overlapped for say 4 hours for the 2x39W then, the other shuts off for the last 2 hours.

More than enough light for your goal and lazy bones.
Careful, lazy makes a clever person to avoid work

Less slight will drive the system slower reduce algae, reduce any possible deficiency, reduce pruning efforts, reduced CO2 demand.everything slows the heck down and and plants adapt very well, to less light.

If you want to increase or decrease efforts, gardening etc, light is the way to do it without a doubt. It's the most stable and easiest parameter to adjust and test. Few test it however.

I have plenty of slow growers, I sold 2 basketball sized java fern needle leaf for 60$ this week, I use about 1.9w/gal in that tank and those lights are 14-16" over the tank surface as well.

That's even a bit too much light also.

Try adjusting and reducing the intensity, the other plants will look better and the slow growers will do very well, you also will no longer waste the energy, electric bill and have algae.

So there's waste, just not quite where some think it is.

This will also help you to reduce labor, save and have nice looking tank.
ADA's tanks are pretty low light also, not if you use Watt/gal, rather, PAR meters, they are also all open top and have the lights raised up rather high.

So they are not comparable in terms of watt/gal.
They also use enriched sediments, not a bad idea for those lazy and not the types that rework and move plants around lots.

Adds another layer of redundancy and back up should you forget to dose.
Hard plumbing also makes any water addition or water change much simpler and easier, given your interest in automation, definitely something to look into, consider the toilet flapper water change idea or a simple ball valve to drain and another to refill, wipe glass, trim, resupply dosing bottles, feed fish etc, while the tank fills.

Makes it an easy process.
You are not the only one that's lazy:redface:
Still, too much automation becomes work, so there's a balance. I like to keep things simple and lazy.



Regards, 
Tom Barr


----------



## plantbrain (Dec 15, 2003)

jmhart said:


> When I typed it, I knew it was going to be confused. I didn't go into detail since it wasn't the purpose of this thread, but my summary of EI should been that it's designed factoring nutrient requirements over a week. I hoped that, for anybody that didn't know, they'd google it to find out full information, rather than simply take what I wrote and say "Oh, i just dump it in all at one since jmhart said so."


Haha, I know you knew that, but wante dto harass you anyhow:redface:
A fun ribbing.

Regards, 
Tom Barr


----------



## plantbrain (Dec 15, 2003)

DarkCobra said:


> I hate to open this can of worms, but...
> 
> My opinion is that EI does NOT eliminate ferts as a variable. It provides a reasonable guess. But it doesn't take into account actual absorption rates of nutrients. More importantly, it doesn't account for other sources of nutrients.
> 
> ...


Fish love worms.
So keep the cans a coming.
EI should prevent nutrient limitations for the commonly grown 300-400s species of plants if all that is the issue is nutrients.
It's certainly non limiting as far concentration goes.

Rates of absorption are not going to excess those ranges I've stated, at least not in any research I've seen. While it's fair game to question that, you need some evidence to suggets otherwise or some results that demonstrate it. I've measured 3-4ppm per day max NO3 uptake.

If fish food is a large part, then perhaps less, if sediment sources are present, again, perhaps less.

The only case is if there is a large denitrification bacteria community, which there might be in some tanks........... that the case might be where there is more than 3-4ppm per day/uptake of NO3.

I've measured pulses of up to 8ppm a day in some systems, but this is not sustained uptake.

The way we address this water column vs plant growth or tissue content involved either % dry weight totals, or tissue analysis where the N content is measured.

I've done plenty of this.

No one else suggesting methods really has to my knowledge.
Fewer yet know the papers for the support for those methods.

I could be wrong, but then Gerloff and Kromboltz would also be off by a large factor. They came to a similar range for their conclusion and where more careful than I was.

About 1/5th full hoagland's solution.
N is around 210 ppm for most solutions.

http://allhydroponics.blogspot.com/2009/02/hoaglands-solution-for-hydroponic.html

1/5th is about 42 ppm.

This is N as NH4 and NO3(different mixes use different ratios).
So 30ppm for the upper range seems plenty for most species, while 10ppm might be limiting for Micrantherum umbrosum.

Still, it would not be strongly limiting and close to Gerloff's 20ppm range for the critical concentrations. Every species will be different, but in general, based on that and my own experiences, it's fairly safe assumption for aquatic plants and nutrients, certainly much better than any other dosing method suggesting and ranges which tend too poo poo EI for being wasteful and excessive.

All while not testing light and running that parameter at a high level(I suppose that's not wasteful/excessive when it suits you?), or worse, assuming they know what their CO2 ppm is, even without any calibrated reference to check their test methods.

No one uses CO2 know gas solutions to reference their test in this hobby. Only a few researchers do.

I'm less concerned about nutrients in other words, non limiting ranges are fairly easy toi hit if that is the goal, practical use shows we do not need as much and if you are close to the critical concentrations(90% of max yield) for nutrients your are okay.

Obviously it's impractical to do a detailed study for all 300-400 species we grow, that's never going to happen, but for the submersed species where that has been done on fast growing weeds, it would appear to be the case.

So in light of any evidence otherwise, I see no issue suggesting EI is non limiting, you can go higher and dose more and see.

I've never once found excess Fe to cause algae.
Haller et al 1977 suggest for Hydrilla, the optimal rates of growth are 8ppm of Fe as ETDA, for max uptake of Fe in tissue, 6ppm was the value.

I add about 5-10X the suggested amount from PMDD.
I've never been able to induce algae with Fe.

So without a reference control, you cannot say about algae causes with nutrients. It's a guess in the wind so to speak, that's all.

http://www.sciencedirect.com/scienc...serid=10&md5=3863ef713ba28b8d7c861a75fbe2ab14

This is an order of magnitude higher than I often suggest and 2 orders higher than most other suggestions for dosing........I might be off as far as limiting value, but as long as I am in the 90% growth yield vs the 100% max, I'm still okay, while they had highest growth at 8ppm, the % difference was not large comparatively.



Regards, 
Tom Barr


----------



## zavikan (Jan 5, 2009)

Thank you. :fish:

Given me a new direction to go in. Never thought that at 2.5 (so many crazy people at 3.5 and above) wpg could be an issue. In all honesty, I've been reading into the lighting issue, as far as PAR and watts and all the rest of that jazz... its heavy reading, just need to read it a few more times.


Off to go replace those crappy tank top legs for the light....mmmm researchin hangin' techniques now! :redface:


----------



## jmhart (Mar 14, 2008)

plantbrain said:


> Haha, I know you knew that, but wante dto harass you anyhow:redface:
> A fun ribbing.
> 
> Regards,
> Tom Barr



:icon_redf.....:thumbsup:


----------



## DarkCobra (Jun 22, 2004)

My concern is with EI is not nutrient limitation, it's nutrient overdose.

I'll demonstrate with a hypothetical 50g, well-planted, high light tank. I found the following guideline:

*40-60 Gallon Aquariums
+/- 1/2 tsp KN03 3x a week
+/- 1/8 tsp KH2P04 3x a week
+/- 1/8 (10ml) Trace Elements 3x a week
50% weekly water change*

I'm going to watch one nutrient - phosphorus.

1/8 tsp KH2PO4 3x a week = 6.72ppm total added P for that week.

Remember I said EI does not take into account nutrient uptake or other nutrient sources. So I'm going to invoke both situations. The tank is well planted, but 50% are slow growers. There's 0.5ppm phosphorus in the replacement tapwater, and a fairly heavy fish load provide more; combined, they provide exactly what the plants use, cancelling out. This is not a far fetched scenario, I've seen it in my own tank; as well as others on the forum which seem to fit this description.

That leaves what we've added. At the close of the week before the water change, the P level is now 6.72ppm. We do our water change to "reset" the tank, which reduces it to (6.72+0.5)/2=3.61ppm.

Close of week 2: (3.61+0.5)/2+6.72=8.77ppm.
Close of week 3: (8.77+0.5)/2+6.72=11.35ppm
Close of week 4: (11.35+0.5)/2+6.72=12.64ppm
Close of week 5: (12.64+0.5)/2+6.72=13.29ppm
Close of week 6: (13.29+0.5)/2+6.72=13.61ppm

It's leveling off, but the result in the long run is our tank is bouncing around on a weekly basis from 7-14ppm.

EI has failed to keep nutrient levels in a sane range, and that tank is going to be an algae farm. Tom, you might dispute that. I recall from years ago you said that you dumped a single large dose of phosphorus in a tank, and it did not cause an algae outbreak. I assume your tank was immaculate and mostly fishless, and that you continued regular water changes which soon eliminated the excess P. I don't think that's a fair test. Try doing it week after week, in a tank with some algae already present, and with a significant fish load. I think you'll get a different result.

If, as you say, large P and Fe overdoses really don't cause algae, we really don't need different guidelines for low/medium/high lighting/planting at all. We could just dose the maximum needed for any conceivable condition. It would simplify things, save everyone a lot of trouble and algae, and the bulk chemicals we use are cheap enough that cost is really a non-issue.


----------



## jmhart (Mar 14, 2008)

DarkCobra said:


> My concern is with EI is not nutrient limitation, it's nutrient overdose.
> 
> I'll demonstrate with a hypothetical 50g, well-planted, high light tank. I found the following guideline:
> 
> ...



EI is meant to overdose nutrients. And, it's not meant to keep nutrients in the same range. It's designed so that nutrients max out at a particular level by weeks end, and then are reset back down low with the next water change.

It is DESIGNED to provide ample nutrients.


----------



## jmhart (Mar 14, 2008)

Dark Cobra,

This will give you a good idea about EI. It is a good summary.


http://www.theplantedtank.co.uk/EI.htm


Of particular relevance to your concerns:



> Estimative Index isn’t about aiming for parameters, but supplying everything to a slight excess of the plants requirements. These are general parameters that plants grow well in and as long as they are reached you shouldn’t have any problems.
> 
> Nitrate 20–30 ppm
> Phosphate 1-3 ppm
> ...



Again, maybe people believe there is a magic formula, but it's really about providing _*enough *_of everything. EI allows you provide enough in an easy manner. From there, you can max out co2. Then, your only variable is light....which most people use too much light anyway. Most people aren't willing to concede that they are using too much light, therefore they blame other factors for their algae woes.


----------



## MarkMc (Apr 27, 2007)

DarkCobra said:


> My concern is with EI is not nutrient limitation, it's nutrient overdose.
> 
> I'll demonstrate with a hypothetical 50g, well-planted, high light tank. I found the following guideline:
> 
> ...


I accidentally dosed over 1/2 tsp of P in my 55. Certainly not an immaculate tank and with a decent fish load. No increase in algae and mind you, the tank was not devoid of it prior. I also don't do 50% reset WCs and dose at the IE rates-no testing-just watch the plants and fish.In your prior posts you spoke of imbalances "triggering" algae. I would think that would qualify as an imbalance don't you? Yeh, so I think I'm doing exactly what you are alluding to: dosing the maximum needed for any conceivable condition. I'm starting to win the battle with algae too.


----------



## DarkCobra (Jun 22, 2004)

jmhart said:


> EI is meant to overdose nutrients. And, it's not meant to keep nutrients in the same range. It's designed so that nutrients max out at a particular level by weeks end, and then are reset back down low with the next water change.
> 
> It is DESIGNED to provide ample nutrients.


I understand that. To provide _ample_ nutrients, a moderate overdose is necessary, because no nutrient must ever approach zero.

But I provided a realistic scenario where EI can produce a _massive overdose_. Would you consider 7ppm minimum phosphorus to qualify as "reset back down low with the next water change"?



> Estimative Index isn’t about aiming for parameters, but supplying everything to a slight excess of the plants requirements. These are general parameters that plants grow well in and as long as they are reached you shouldn’t have any problems.
> 
> Nitrate 20–30 ppm
> Phosphate 1-3 ppm
> ...


The guidelines here say _slight excess_, and list an upper range. 7-14ppm phosphate is out of that range and definitely not a "slight excess".

Ironically, by following EI dosing protocol in a certain tank, the result violates EI's own guidelines.

I'm not trying to say EI is a bad system. In fact, I use it as the basis of my own tank regimen.

All I'm saying is that although EI is a good starting point and works well for most tanks, _it is not a perfect universal solution_, and sometimes must be adjusted. This should be a simple concept, but the responses I get whenever I suggest it make me feel like I've committed some kind of heresy.


----------



## JDowns (Mar 6, 2008)

DarkCobra said:


> I'm not trying to say EI is a bad system. In fact, I use it as the basis of my own tank regimen.
> 
> All I'm saying is that although EI is a good starting point and works well for most tanks, _it is not a perfect universal solution_, and sometimes must be adjusted. This should be a simple concept, but the responses I get whenever I suggest it make me feel like I've committed some kind of heresy.


I'll go back to my original statement. If someone else has drawn this conclusion they haven't read EI or they fail to understand.

Common sense at some point has to seep in, although I will concede that some folks are hopeless. It's been stated ad nauseam that the levels are not set in stone. If you have less plant mass dose less, have an encriched soil dose less, will the additional nutrients cause a problem - obviously not (which has been shown over and over and over). And from EI's article 

_"The tap water has nutrients in it, then you do not have to dose these nearly as much, this is actually a good thing! Why take something out and then add it back again?" _


----------



## plantbrain (Dec 15, 2003)

I think it's a good discussion to consider and see what is going on.

I like figures and graphs, they tell much more than my poorly explained ideas:redface:










This figure is good and the x axis' "concentration in dry matter" could also be used for CO2 or light and growth/yield comparisons. they have similar shaped curves and critical levels.

The region D and C are good areas to target, they offer the widest and easiest targets to hit. 

Other methods seem to target either A or B regions, which is much harder to manage and maintain in those narrow ranges. You can go from very good growth, to stunted tips. Then they blame Fe, ratios, K+, PO4 etc etc........but they are limiting things from the start. Bad assumptions.

More about this and sediments below as a better method:










In this figure, we can get another idea of the same figure above, the curve is not as steep, and we can see that the limitation intensity is not on/off, rather continuous and gradual over the concentration ranges.
Plants can recycle nutrients within their tissues as well and fish waste and tap can be other potential sources in aquariums, so things might not be as desire as some might suggest.

Now, the sediment + water column/EI:

Here's another using N and soil + liquid fertilizer:










We can see another source, which allows us to dose LESS fertilizer but still get a large yield/rate of growth. Now sediments rich in NPK/traces can do the same thing and fish waste can play a role, as well as tap water.

However, if you only have a max yield, adding more will not hurt the system nor increase the yield.

It's already at that max growth rate.
That is the definition of the max growth, adding more of that parameter will no longer increase rates of growth, you are done with that parameter.

For farmers, fertilizers are costly, or organic farmers, manure is costly, or sustainable methods: crop rotation is time not producing the higheer value crops I could make more $ with. So they have real management issues and want to use "just enough" for economic reasons. The volumes are huge and thus the cost are and the impacts on the environment.

A few gallons of PO4 at .5ppm vs 2ppm is not much of an issue on any of those points.

If you think so, then you should give up the hobby and buy a bike and sell the car. The energy alone used for the aquarium causes far more risk and impact to the world at large. Still, I'm not saying to dump PO4 down the drain either.

I like just enough for aquariums as well.

But...........my version of what is "just enough" is based on the graphs above, not dogma, semantical drivel, old tired myths, goading folks into quackery, telling them what they want to hear and pooing on others to do it.

Some tanks will use less, some more, but virtually none will use more than EI.
So that catches more aquariums than any other method as far as nutrients.

Same for Hoagland's solution for hydroponics and in plant research.
But........it does not imply that every farmer needs Hoagland's solution!!!!
They can and should modify it to suit their system, their soil, their method of agriculture(sustainable, organic, conventional etc), their specific crops that they raise.

I'm not sure it this helps, but I hope so:tongue:

Regards, 
Tom Barr


----------



## DarkCobra (Jun 22, 2004)

Tom, that's a great post. Thank you for that, and for remaining patient with me while others might infer I'm hopeless and lack common sense.

Bear with me a bit longer, and allow me to describe why I cannot resolve what you're saying with my own experiences.



plantbrain said:


>


I have a tank dosed according to EI guidelines. I believe all nutrients are present in adequate amounts (ie, all on the 'D' part of the curve), but I am getting too much algae; specifically that which people commonly attribute to too much phosphorus.

So I test it, with the understanding that the tests can be incorrect, but believing I can still gain some useful info. All nutrients test within the suggested ranges, except phosphorus which reads 5ppm. I would say that is still on the 'D' curve, but it is higher on the 'D' curve than the rest.

Given the evidence from the algae guides and the tests, I balance my nutrients by reducing phosphorus. And it works - the algae goes away, plants remain healthy and growth is not noticeably reduced. If I later add the phosphorus back, the algae comes back too.

But if I understand you correctly, nutrient balance is irrelevant as long as there is neither deficiency or toxicity.

If it's deficiency, then nutrient(s) other than phosphorus were limited. And if balance is irrelevant, then reducing phosphorus should have no effect until I reduce it to the point of limitation. That would have the effect of slowing plant growth slightly, possibly unlimiting the previously limited nutrient(s). But overall, I am adding less nutrients than before and plant growth is reduced; this should not have a net positive effect on my tank as I am seeing.

If it's toxicity, then phosphorus was actually in a toxic range. But this would mean an extremely high level, and I don't see how this is possible while following EI dosing guidelines. I have checked and double checked to make sure I am not dosing in error, and my prior posts should demonstrate I am competent with math and measurements.

Neither of these possibilities seem to fit.

Can you see why I am led to the conclusion that _nutrient imbalance without deficiency or toxicity_ can cause algae?

If I'm wrong, _how_ am I going wrong? Please relate your description in a way that it applies to the experience I've described if possible.


----------



## StillLearning (Dec 29, 2009)

DarkCobra I am right there with you wondering this as well. Tom thanks for explaining all this even though I have not posted I have been reading this and wondering also.


----------



## JDowns (Mar 6, 2008)

DarkCobra said:


> Tom, that's a great post. Thank you for that, and for remaining patient with me while others might infer I'm hopeless and lack common sense.


I was not inferring anything :confused1:. Sorry if agreeing with you, as I quoted you, and supported my comment by a direct quote from the original EI post has caused you great confusion.

Now that's inferring. :flick:


----------



## DarkCobra (Jun 22, 2004)

JDowns said:


> I was not inferring anything :confused1:. Sorry if agreeing with you, as I quoted you, and supported my comment by a direct quote from the original EI post has caused you great confusion.
> 
> Now that's inferring. :flick:


Guess I read that wrong, then. I apologize for inferring you were inferring.


----------



## JDowns (Mar 6, 2008)

DarkCobra said:


> Guess I read that wrong, then. I apologize for inferring you were inferring.


No worries its the internet and it happens :icon_smil.

For your P example I personally haven't seen an imbalance with higher levels of dosing than standard EI, and I'm not the only one who doses additional levels. I've dosed for nearly a year double the dosage that EI calls for, even with a nutrient rich substrate. These levels for me keep GSA off the glass and slow growing plants. I haven't reached any critical point of over saturation to cause ill effects in plants or an algae explosion as some folks claim would happen. I've found its far more important to keep moderate light levels (40-60 umols at the substrate) with good consistent CO2 then it is to worry at all about anything nutrient related. In this context I'm excluding CO2 as a nutrient although it should be considered as a nutrient. Another aspect I think that does not get enough consideration is "good husbandry". Cleaning of filters, pruning/preening plants, occasionally vacuming the substrate sections at a time, and if wood is used occasionally taking a stiff brush to it. Water changes to me are more important for removing organic waste rather than removing excess nutrients. IMHO in a normally algae free tank and no other parameters have changed, light and CO2. A buildup of organics can cause an algae bloom. I know from experience if I ignore filter maintenance or allow a buildup in the substrate, BBA is looming and alot more effort than a water change is in store to get the tank back to square one.


----------



## MarkMc (Apr 27, 2007)

JDowns said:


> No worries its the internet and it happens :icon_smil.
> 
> For your P example I personally haven't seen an imbalance with higher levels of dosing than standard EI, and I'm not the only one who doses additional levels. I've dosed for nearly a year double the dosage that EI calls for, even with a nutrient rich substrate. These levels for me keep GSA off the glass and slow growing plants. I haven't reached any critical point of over saturation to cause ill effects in plants or an algae explosion as some folks claim would happen. I've found its far more important to keep moderate light levels (40-60 umols at the substrate) with good consistent CO2 then it is to worry at all about anything nutrient related. In this context I'm excluding CO2 as a nutrient although it should be considered as a nutrient. Another aspect I think that does not get enough consideration is "good husbandry". Cleaning of filters, pruning/preening plants, occasionally vacuming the substrate sections at a time, and if wood is used occasionally taking a stiff brush to it. Water changes to me are more important for removing organic waste rather than removing excess nutrients. IMHO in a normally algae free tank and no other parameters have changed, light and CO2. A buildup of organics can cause an algae bloom. I know from experience if I ignore filter maintenance or allow a buildup in the substrate, BBA is looming and alot more effort than a water change is in store to get the tank back to square one.


I agree.


----------



## DarkCobra (Jun 22, 2004)

Both of you are having great results with higher nutrient levels.

I'd like to try it, but as long as I don't know the cause of my existing issue, it's a variable that might invalidate the result of such a test.

Jdowns, thanks for the reminder about "good husbandry". I think I do a good job, and I don't think that explains my issue.

But I'm going to make sure. So I will give my tank an extra-thorough cleaning in addition to my normal maintenance, then bring my phosphorus dosing back up to normal EI, and see what happens. It will take a week or two to know the result.

In the meantime, I'm still open to other suggestions. In particular, I'm hoping for Tom's opinion. No offense to anyone else, but he's got the scientific data.


----------



## zavikan (Jan 5, 2009)

Hey, just to recap the initial problem that resulted in this posting...


Raising the light seems to have done wonders. The algae is disappearing in many places. The plants are growing with more color and the leaves are more compact. Even the HC seems to be doing just fine.

Lamp is currently 6" above the water level. This is more then double the height of when it was on the coralife legs.


----------



## DarkCobra (Jun 22, 2004)

That's great Zavikan!

Sorry for having gotten your thread so far off-topic btw.


----------



## plantbrain (Dec 15, 2003)

DarkCobra said:


> Both of you are having great results with higher nutrient levels.
> 
> I'd like to try it, but as long as I don't know the cause of my existing issue, it's a variable that might invalidate the result of such a test.


Never let fear get in the way of the unknown, that's how we learn.
Stick with small steps and see what other things you can answer that will rule some things out and get you a bit closer.

You do not learn of cause without turning over many many stones looking for that answer. Even then, you are left with a few possible answers that are most likely.

In the meantime, I'm still open to other suggestions. In particular, I'm hoping for Tom's opinion. No offense to anyone else, but he's got the scientific data. [/QUOTE]

Really?
I thought it was more common sense and few papers:icon_redf

There's a lot more to growing plants than nutrients.
Since we are submersed, now CO2 is much more limiting and thus acts as nutrient.

Good accurate referenced measuring of CO2 is entirely absent in this hobby.
So little can be said directly.

Does not stop many from trying.

Folks end up spending far too much time on nutrients and micromanagement. I like the soil use and ADA AS, worm castings etc for this reason, folks add it and stop frigging having a cow related to water column dosing.

Lighting is another issue that extremely few have bothered to test until very recently. PAR meters run 200-300$, folks share them etc. Now you can at least compare good healthy tank examples for nutrients and light.

Healthy tanks BTW are required for references, or serve as a "control".
If you cannot produce such a tank, you lack the control in the 1st place:thumbsup:

Again, does not stop many from trying to worm their way into claiming they are doing some sort of test and Science.

So with good nutrients and testing with references, light testing, now we can close in on the last piece, the CO2.

So how might CO2 change in response to light intensity and plant growth?
Tropica did an article on CO2 and light that explains that well.

http://www.tropica.com/go.asp?article=836

Read all 4 parts, there's a good table that explains how plants respond to different light and CO2 combinations.

As you can read at the end of this article, they suggest using low light and high enriched CO2 for the best plant growth and management. ADA does indirectly(they do not say it, but their system is precisely that, low light and CO2), George Booth, myself, many others have long stated this.

But..........folks think "more light is better" , but then think limiting nutrients is some "key". They'd be better served by limiting light and adding non limiting nutrients/CO2. I've been nagging this point for many years, with many arguing extensively with me over silly nutrients, when they have no idea of the larger picture.

If you reduce the light, then you have less demand for CO2 and nutrients.
So that alone fixes the issue.

However, you can also look at it, by realizing that at higher light, you have more trouble managing CO2 and nutrients(more CO2 than nutrients, adding more nutrients is rather simple/easy to do).

So, if you can master extremely high light, medium light, low light and non CO2/Excel type methods, then you have a better understanding of what is going on.

There's a trade off for going extreme light, it will require a lot more work, effort, whereas a non CO2 no water change tank might be too slow and you might not mind a little more work to get there faster.

You can limit nutrients and affect CO2 and light use efficiency also, but it's a harder method than using light which is the most stable parameter we have to work with for our tools for management, it also is the largest cost energy wise for most aquariums. So if it's _really about waste and excess_, you'd be wise to start there. 

I care a bit less about that, rather, more about reducing the no# of issues and failures for new folks coming into this hobby. The higher the success and tertention rate, the better.

So for most, this means low light, good CO2, good management of aquariums(clean filters, water changes etc, not a frigging chem class and micromanagment).



Regards, 
Tom Barr


----------



## plantbrain (Dec 15, 2003)

zavikan said:


> Hey, just to recap the initial problem that resulted in this posting...
> 
> 
> Raising the light seems to have done wonders. The algae is disappearing in many places. The plants are growing with more color and the leaves are more compact. Even the HC seems to be doing just fine.
> ...


If you can switch to open top and wire suspension, this gives really nice abilities to throttle the light and adjust it infinitely.

Ideally, we would all like a nice rheostat that could reduce the energy to the bulbs and dim and adjust them without an open top as well. LED's have this potential but are a ways off from being reasonable in cost.

I do this for every tank I set up:










When I'm around, have time, etc........in the mood .........I can lower the light and garden more intensively.

When I leave for vacation, messed something up, neglected the tank that led to algae etc, I simply raise the light up. 

Slows everything down and is more stable than dialing in nutrients/CO2, since light drives everything else downstream, this makes management much simpler, easier, more stable with less error.

Some folks want hobbyists to use their "system" and swim upstream using the nutrients, while still keeping that same light or CO2, perhaps they adjust it, but they still do not understand how it all works together. It can work, but it's not as logical or shows an understanding of how plant growth occurs, nor is as easy management wise.

But what do I know?

Regards, 
Tom Barr


----------



## hbosman (Oct 5, 2006)

plantbrain said:


> Never let fear get in the way of the unknown, that's how we learn.
> Stick with small steps and see what other things you can answer that will rule some things out and get you a bit closer.
> 
> You do not learn of cause without turning over many many stones looking for that answer. Even then, you are left with a few possible answers that are most likely.
> ...


Really?
I thought it was more common sense and few papers:icon_redf

There's a lot more to growing plants than nutrients.
Since we are submersed, now CO2 is much more limiting and thus acts as nutrient.

Good accurate referenced measuring of CO2 is entirely absent in this hobby.
So little can be said directly.

Does not stop many from trying.

Folks end up spending far too much time on nutrients and micromanagement. I like the soil use and ADA AS, worm castings etc for this reason, folks add it and stop frigging having a cow related to water column dosing.

Lighting is another issue that extremely few have bothered to test until very recently. PAR meters run 200-300$, folks share them etc. Now you can at least compare good healthy tank examples for nutrients and light.

Healthy tanks BTW are required for references, or serve as a "control".
If you cannot produce such a tank, you lack the control in the 1st place:thumbsup:

Again, does not stop many from trying to worm their way into claiming they are doing some sort of test and Science.

So with good nutrients and testing with references, light testing, now we can close in on the last piece, the CO2.

So how might CO2 change in response to light intensity and plant growth?
Tropica did an article on CO2 and light that explains that well.

http://www.tropica.com/go.asp?article=836

Read all 4 parts, there's a good table that explains how plants respond to different light and CO2 combinations.

As you can read at the end of this article, they suggest using low light and high enriched CO2 for the best plant growth and management. ADA does indirectly(they do not say it, but their system is precisely that, low light and CO2), George Booth, myself, many others have long stated this.

But..........folks think "more light is better" , but then think limiting nutrients is some "key". They'd be better served by limiting light and adding non limiting nutrients/CO2. I've been nagging this point for many years, with many arguing extensively with me over silly nutrients, when they have no idea of the larger picture.

If you reduce the light, then you have less demand for CO2 and nutrients.
So that alone fixes the issue.

However, you can also look at it, by realizing that at higher light, you have more trouble managing CO2 and nutrients(more CO2 than nutrients, adding more nutrients is rather simple/easy to do).

So, if you can master extremely high light, medium light, low light and non CO2/Excel type methods, then you have a better understanding of what is going on.

There's a trade off for going extreme light, it will require a lot more work, effort, whereas a non CO2 no water change tank might be too slow and you might not mind a little more work to get there faster.

You can limit nutrients and affect CO2 and light use efficiency also, but it's a harder method than using light which is the most stable parameter we have to work with for our tools for management, it also is the largest cost energy wise for most aquariums. So if it's _really about waste and excess_, you'd be wise to start there. 

I care a bit less about that, rather, more about reducing the no# of issues and failures for new folks coming into this hobby. The higher the success and tertention rate, the better.

So for most, this means low light, good CO2, good management of aquariums(clean filters, water changes etc, not a frigging chem class and micromanagment).



Regards, 
Tom Barr[/QUOTE]


Tom,

I know you stated the above many times but, for some reason, it just became a lot more clear to me this time. Thanks for stating it again.

Henry (the hard head) :icon_redf


----------



## DarkCobra (Jun 22, 2004)

plantbrain said:


> Never let fear get in the way of the unknown, that's how we learn.
> Stick with small steps and see what other things you can answer that will rule some things out and get you a bit closer.
> <snip>


That all makes perfect sense.

I will assume for now that I have come to an incorrect conclusion based on my observations.

I'm proceeding as follows:

Cleanliness: Very thorough tank cleaning performed as of yesterday.

CO2: My drop checker also came in yesterday. It said my CO2 wasn't as high as I thought. I improved my CO2 diffusion scheme, and the drop checker now reads green/yellow. No signs of fish distress, so I will further increase the CO2 until I see that, then back off. The drop checker will then be used to indicate CO2 relative stability, not as an absolute measurement.

Light: I have 34W of T8 with white plastic "reflectors", sitting on a glass shield, over a 46g bowfront. I understand that reducing this could make things easier by reducing need for CO2/nutrients; but I consider this so little light that I'd rather fix the CO2/nutrients. 

Nutrients: Once I've established max CO2, I will play with these. If I again find that phosphorus appears to be causing problems, instead of reducing phosphorus, I will instead _increase_ all other nutrients.

Anyone see fault in this plan?

Funny you should mention this:



plantbrain said:


> Ideally, we would all like a nice rheostat that could reduce the energy to the bulbs and dim and adjust them without an open top as well. LED's have this potential but are a ways off from being reasonable in cost.


I just ordered a toy - a three bulb fluorescent dimming ballast. For $20.50 shipped, it's worth playing with.  There are more available if anyone is interested, I'll post in DIY with details.


----------

