# Truth About GDA?



## manofmanyfish (Mar 31, 2008)

Truth About Green Dust Algae?

My recent experience with GDA leads me to believe that no one knows definitely how to put an end to GDA. That’s ok, it’s a living thing and that makes it complex enough that I can appreciate that it doesn’t fall into the Easy category. Shame on me for thinking, it's a problem (like a flat tire) and I just want instructions on how to fix it.

So, shouldn't we just admit that we don’t know how to get rid of it.

What is the most accurate statement that we can make about GDA?

a. We (the aquarium hobbyist) fully understand the factors that cause GDA and know how to get rid of it. A specific set of directions, if followed will be successful in defeating GDA, 100% guaranteed.

b. We fully understand the factors that cause GDA and know how to get rid of it, but only under certain specific situations and conditions.

c. We do not fully understand the factors that cause GDA, but can offer some suggestions that may or may not work. Successful solutions vary. What works for one individual will not work for everyone. 

d. We do not understand the factors that cause GDA and accept that you may not be able to defeat GDA. The best you can hope for is to control GDA by vigilant cleaning and good housekeeping. It is not known why GDA eventually goes away. It appears that it either dies or goes into long dormant states. Neither of which happens as a result of anything that you do.


----------



## plantbrain (Dec 15, 2003)

"e" try to figure out things and some resolution to questions and test it yourself:thumbsup:

See if you can induce it. 
I've been able to induce it maybe 30% of the time at best with inoculations. 
I have no issue getting rid of it however nor keeping it gone.
Some have. 

Same with any algae.
Your own frustration leads you to think and believe differently than you might otherwise. 

I've gone after it pretty aggressively by wiping it off, but that never really helped that much. A blackout + Excel + good growth of the plants, good CO2, UV+ mechanical filtration, reduction in light, adding rubber nose plecos etc, good pruning and general care seem to prevent all types of algae.

You can do quite a few things to beat on algae.
Harass it, and maintain good plant health.

Why is grows sometimes and then goes away from then on, or some have it come back every so often, I'm not certain. No one is, it's now your question so you figure it out and test it to answer it. 

But as far as how to get rid of it, I've suggested several methods I know have worked well many times. I nor the folks I helped had reinfestations.
A few likely had many other issues so they had other problems that contributed to general algae issues. Hard to say, that is true for any algae issues however, in person is easier to catch issues, on the webm who knows, these folks have many issues and problems growing plants, somne hardly ever do and have green thumbs.

Many ways to screw things up, but do not base the conclusions on that alone. You need a success to show why something works, or to induce GDA etc. I have not had good success with this alga there.

But that is the criteria for finding out why an alga appears. 
So now you have a method and some things to consider and look at...........and test.




regards, 
Tom Barr


----------



## Wö£fëñxXx (Dec 2, 2003)

Have you ever seen GDA in a low light tank? neither have I.
Green Spot, yes, GDA, no.
I can induce it with a lot of light, every time.

It's not that puzzling or mysterious,.



> What works for one individual will not work for everyone.


I don't agree with that at all, a box of water is just that, what matters
is who is overseer.
I think it really depends on _who_ is maintaining the tank and what
you know or the experience one may or may not have.

If I have 15 or 100 tanks that do not have it, and someone has one tank
and can't get rid of it what does that mean?

It really isn't that complicated by far.


----------



## jaidexl (Sep 18, 2006)

I've had a long lived GDA issue in one tank, I can control it with light. It's surprisingly resilient, in this case, to lower levels of light in terms of wpg, but fixture efficiency could be more than adequate. There is a point I can drop wattage to that halts the reappearance of GDA, but also slows plant growth to near el-natural speeds and causes leggy growth in some ground cover species.


----------



## manofmanyfish (Mar 31, 2008)

Well, sure we do know a lot of factors that are involved. I guess the answer is "a" if we turn the lights off.


----------



## manofmanyfish (Mar 31, 2008)

"e"...not really answering the question.



plantbrain said:


> I have no issue getting rid of it however nor keeping it gone. Some have.


 "Some have", I think that's understating the numbers of people in this hobby who have had great difficulty in erraticating this algae.



plantbrain said:


> But as far as how to get rid of it, I've suggested several methods I know have worked well many times. I nor the folks I helped had reinfestations.


Some people are cured of cancer with some treatments, but it doesn't work all the time, for every individual, even if the cancer is the same. Do we truely understand it, if we can't reproduce our results....every time.


----------



## sewingalot (Oct 12, 2008)

I don't think algae is ever going to be truly understood. I think it is a luck of the draw. I recently set up 2 different 10 gallons. One was low light (28 watts) and one is high light (65 watts). I set them both up at the same time (about three weeks ago). The 28 watts have been relatively free of algae and good growth. The 65 watts started showing GDA within 3 days. Never have gotten rid of the GDA. But, this is only my experience.


----------



## KDahlin (Mar 12, 2007)

Wö£fëñxXx said:


> Have you ever seen GDA in a low light tank? neither have I.
> Green Spot, yes, GDA, no.
> I can induce it with a lot of light, every time.


I have GDA in all of my tanks, one is a non-CO2 1.5 wpg tank.


----------



## Homer_Simpson (May 10, 2007)

The only time that I ended up with GDA in my tanks was when I couldn't leave well enough alone and decided to monkey around with light and increasing light intensity. In one tank, that led to a real dog's breakfast and I have since lowered light intensity to pre-GDA levels to see what happens. In my other tanks when I lowered light intensity to pre-GDA levels, I noticed that within about a month the GDA receded. Whether it has only gone dormant, signifcantly slowed down in growth so as not to be visible is another issue. 

What I can say with 100% certainty is that I have yet to see it rematerialize in my 40 gallon, almost 2 years after it made its appearance. I am not sure what specifically caused it to recede and disappear. I was engaging in agressive algae treatment measures when GDA, black beard algae and thread algae all appeared at the same time. I did 2x weekly water changes. double dosed Excel daily, reduced light intensity, manually removed as much algae as possible and trimmed off badly infested leaves/removed plants too far gone, threw in a Albino Bristlenose Pleco and Siamese Algae Eater. It took a good 3 months to notice a difference. The tank is now 100% algae free and plants are growing faster than I can trim them, sell them, or otherwise give them away. If I had to speculate as to the one thing that turned the tables on Algae including GDA, I would have to say "balance"(likely a combo of light, c02, and nutrients/ferts) and subsequent healthy plant growth.

Sorry folks, I don't share your pessimism. I believe GDA can be defeated, but you have to have a lot of patience and be willing to fight the good fight to defeat it.


----------



## o snap its eric (Jan 12, 2004)

algae is one of the simplest organisms. It survived past the dinos so for us to complete killing it is virtually impossible. All we can do is keep it at bay and not allow it to over run out tanks. We as hobbyist have found a nice formula to suppress algae but just as algae was able to survive past the dinos they are surely going to find a way to get around out method of suppressing algae due to their adaptive nature.

Why not invest some ottos or algae eating fish to compliment your algae battle?


----------



## plantbrain (Dec 15, 2003)

manofmanyfish said:


> "e"...not really answering the question.


It is your question, I just suggested you go about testing it to find this "truth" that you seek. I found out what species it was. I told folks. You learn a little bit and go from there. 



> "Some have", I think that's understating the numbers of people in this hobby who have had great difficulty in erraticating this algae.
> [/qute]
> 
> Those with issues will post a lot more than those without, so no, I think far more folks do not have issues with GDA that do have issues with it.
> ...


----------



## Homer_Simpson (May 10, 2007)

plantbrain said:


> ..The one factor I could not be conclusive about was*CO2 and bacteria cycling*.
> GDA did not seem to reappear after it left when I went back and changed the CO2 either...


I would be curious to learn more about what you mean by this. Could you elaborate. Also, what is your experience with Green Dust Algae and emersed dry startup method and subsequent flooding? In other words, did any tanks that were started emeresed than flooded develop green dust algae? Thanks.


----------



## jmhart (Mar 14, 2008)

There is a lot of anecdotal evidence out there about every kind of algae. Phosphate this, potassium that.......I feel comfortable saying that for 90% of all alage problems, if you just cut down your light you'll be fine...that's a sure fire solution nearly all the time(I understand you are looking for something definitive, but for all algae I can't say it's always the same thing). 

As far as GDA, I can say this. I have a 46g tank with 2x96w of PC lighting, maxed out co2(as in maxed out I mean I pumped it up until my fish gasped, and then backed it down until things returned to normal). In this room, there was directly sunlight. My wife made new curtains effectively blacking out the room. Boom, within a few weeks, no more GDA. So, backing down the light fixed my problem. 

However, the argument can also be made(as it often is) that the GSA simply finished it's life cycle. It's hard to tell. This was nearly a year ago...not nearly, it was a year ago....and I haven't seen GSA in that tank since.

If you want high light, you've got to figure out a way to go higher with your co2. However, instead of doing that, I recommend going lower with light. People are impatient. They want their tank full within a month, so they go 6 wpg over a 55g and then go crazy complaining about algae problems. Just back down the light. No need to have that much light.


----------



## sewingalot (Oct 12, 2008)

plantbrain said:


> The one factor I could not be conclusive about was CO2 and bacteria cycling.
> GDA did not seem to reappear after it left when I went back and changed the CO2 either. This was true back 4 years ago as well. Perhaps it just took awhile for the plants to get going and build up good growth with good CO2 first.......still, there are quite a few species of algae that appear when CO2 drops.


I am inclined to agree with this statement after my "mini" experiment on GDA. Co2 is definitely a factor. But to what extent, I am uncertain at this point. I am interested to see what happens in the end.


----------



## jaidexl (Sep 18, 2006)

My 1yr long battle is finally over, I think I mentioned before that I lowered my light to make it happen. This is after a long stand off of staying the course with dosing and pumping CO2 until the DC was useless and I had to use the fish for measurement. I watched it go through more life cycles than a rabbit and keep coming back until I started lowering my light.

Just recently I decided to cut the CO2 on the same tank, within a few weeks of the GDA subsiding, also stopped dosing completely except for resetting some levels after a water change. The GDA still vanished. Luckily all my species can handle the light level, I'm only running 78w T5HO now over 65gl, whereas it used to be 192w for a year of success before the GDA started.


----------



## i4x4nMore (Mar 31, 2008)

*My quest to learn about algae*

Hi All &

manofmanyfish, I hear your frustration and I empathize with you. I had the same major questions as you - up until about a year ago. But last year, I began a quest to seek some answers myself... 

*Following Advice*

The advice I followed wasn't so much an a-to-b set of instructions, but more of an philosophical approach to observing cause and effect relationships in the planted tank. Most people are content to maintain an algae-free tank if they already have one, but fewer are willing to induce algae in that algae-free tank in order to learn something from the process. (PlantBrain wrote something like that, at least once, and I took it to heart.)

I can tell you this, you're never going to arrive at the answers you seek about algae if you're always simply reacting to the problem; The remedy-approach does not really teach anything. These tanks we keep are complex bio-chemical systems and many variables affect the current state of your tank. That's why it's difficult for one person's solution (remedy) to be applied to your exact situation. 

For my personal path, I needed a foundation on which to start.... otherwise, it's a catch-22: _How do you induce algae if you always already have it, right?_ I needed to learn to keep and maintain algae-free tanks to start with. From there, I could change variables one at a time and observe the results. 

For this, I took some advice and I treated it as the foundation on which to run my tanks. It's a simple relationship that PlantBrain has written about many times... It's sometimes written like this: Light=>CO2=>Nutrients. 

I'm not going to go into detail here but, on the surface, what it means is simple: The amount of LIGHT you supply drives the amount of CO2 you need; which, in turn, drives the amount of NUTRIENTS that need to be supplied to the plants - all of which seems to be intricately related to how algae grows

Now, when I started this, I didn't know if PlantBrain's assertions were true or not. And it wasn't straight forward for me to implement the simple relationship of "light-co2-nutrients", at first. But what I liked about the postulation was the fact that it could seemingly be applied to any planted tank regardless of the difference in variables. And in the interest of learning, I took the long/hard approach for some things. 



*My Quest For Learning About Algae*

What follows is an outline of my basic (tedious?) path to learn about algae:


Adopt a methodology that has been shown to produce algae-free tanks. For this, I decided to use the Estimative Index (EI) proposed by PlantBrain. I didn't know if it would work, so I tested it.
Develop a system to control the lighting: I decided to use metal halide bulbs. I set them up in a way that the intensity could be controlled using various wattages, distance, and neutral density gels.
Stopped using watts per gallon to quantify light: Instead, I relied on a PAR light meter. It effectively measures the amount of light available for photosynthesis. This eliminates variables such as light distribution, water depth, water turbidity, and bulb efficiency. You can measure under the water, at the plant.
I used pressurized CO2 in all tanks with pH controllers - for consistent CO2. And I built a DIY drop-checker to verify the amount of CO2 in the water column, to maintain my target value.
I tested and calibrated the pH probes frequently.
I started making RO water (99% pure water) and manually added minerals and nutrients to create my "aquarium water" for each and every water change... in this way, you know primarily what's in the water, and how much, since you added it.
I learned how to make dilute solutions of macro and micro plant nutrients for daily additions (Estimative Index)
I kept records of amounts and schedules of daily nutrient additions and water changes
For my substrate, I used garden soil topped by small grain gravel. I sent the garden soil off to a lab to have it tested for composition, nutrients, and toxins. It turned out to be a moderately rich loamy-clay soil with no toxic compounds detected (that they tested for, anyway). I also soaked the soil for eight weeks before using.
Once actively applying the Estimative Index, I started testing for phosphates and nitrates at every water change and recorded their values. This allowed me to make adjustments to the EI schedule.
I learned how to calibrate my phosphate and nitrate kits so I could have some certainty of the observed measurements.
Once plants really take off and start growing like crazy, keep them trimmed and maintained.


After implementing all of the above, I finally started maintaining algae-free tanks. And now I was free to change certain variables (one at a time) and observe the reactions. Here's a few tips about experimenting:


Be sure to only change one variable at a time (light, or co2, or nutrients). Otherwise, you can't draw any meaningful conclusions.
You must keep a control tank so that you can have something to compare against. This control tank is your algae-free tank (that you've learned how to maintain)
Allow sufficient TIME after changing a particular variable. The biological and chemical systems in a planted tank are relatively slow. They take time to reach a steady state. In this case, time frames can equal several weeks, not days.
Always verify your test kits and meters against known solutions.
Don't be afraid of the algae... be "amused" by it. In the interest of learning, encourage it; grow it, watch its cycle; see how one algae gives way to another.


*Some Things I've Verified*

Here are some things I've learned/verified on my personal quest:


In a planted tank rich with co2 and non-limited nutrients, high nitrates and phosphates do not CAUSE algae.
Evenly distributed co2 in a tank is critical. The co2 levels, even in a small tank, are not evenly distributed.
Controlling the light, is the easiest way to affect changes in your tank
 Garden soil can provide almost everything my plants needed, but the biological nutrient cycle is slow. With increased light and co2, the plants use more nutrients faster. The biological system alone cannot keep up with the demand. In my experience, to avoid algae, a non-co2 tank with soil must use lower light levels and a minimal fish/invert load.
 Following the relationship "Light=>CO2=>Nutrients" has yielded algae-free tanks for me.
In my observations, even algae competes with other algae. I've seen "slime" give way to "mattes", "dust" give way to "fuzz", give way to "hair".... Red replaced by Brown replaced by Green, replaced by Black.
And when I restore the "light,co2,nutrient" relationship, all the algae dies away (or is severely limited)
Keep in mind this takes many many weeks.... not days.
The presence of algae in my tanks is now an "indicator"... i.e. one of the variables has changed. Hmm, which one? Light? CO2? or Nutrients?
The quest then becomes "restoring the balance".... not applying some remedy.

*No Long Post Should Go Without Images!*

Here are some pics so you can see where I'm coming from, and what kind of tanks I keep. The pics show two of my tanks: a 15 gal tall, and a 5 gal cube. They are both run with injected co2, metal halide lighting, and Estimative Index dosing.

Cheers!


----------



## Hoppy (Dec 24, 2005)

Very interesting writeup. And, nice looking tanks too. One comment: the drop checker has to actually be in the tank before it will continue to be accurate. Otherwise water will distill from the warmer side, probably in the tank, and condense in the cooler side, probably outside the tank, diluting the KH of the water there. If the "bulb" part is also in the tank there is no temperature difference, so no net transfer of water. This may be a very minor effect or a significant effect, depending on the temperature difference.


----------



## Homer_Simpson (May 10, 2007)

Beautiful tanks and excellent write-up i4x4nMore. This is pretty much what I have learned. I think the problem is that there are lots of people still holding on to myths and fallacies about what causes algae and how to deal with it and they are not willing to test and seek solutions themselves, or at the very least understand that it is largely related to a balance resulting from relationship between light, c02, and nutrients. It is interesting how people will still argue and insist that algae is due to high nitrates or phosphates without even looking at light intensity of c02. To those, I say, that is fine that you choose to debate the issue, but provide some evidence to back up your claims or frakken shut the h*ll up instead of just parroting what you heard or read!


----------



## Wö£fëñxXx (Dec 2, 2003)

KDahlin said:


> I have GDA in all of my tanks, one is a non-CO2 1.5 wpg tank.


_Why_ do you have GDA in "all" of your tanks?

I don't have GDA in any of mine, does this mean I should have it also?

What is your conclusion?



i4x4nMore said:


> The amount of LIGHT you supply drives the amount of CO2 you need; which, in turn, drives the amount of NUTRIENTS that need to be supplied to the plants - all of which seems to be intricately related to how algae grows


I call this the chain of command, light being the determining factor,
or the dividing line.

Place a bucket of water in the sun for a few days, what happens?
the water turns green, empty the bucket and the bucket will have
a green silhouette of where the water was. 

Light sets it all in motion, we then have to understand what is needed
for balance. plants, nutrients, the right amount of light, and if the light
reaches a certain threshold then the demand for C02 & nutrients is arrived
which then must be within a certain equilibrium of the lighting.


----------



## nkambae (Feb 26, 2007)

*good stuff here!*

Plantbrain, Wö£fëñxXx, Homer, Hoppy, jaidexl... and now a new fave... 4X4. Good stuff all. Does this deserve sticky status? 

stu


----------



## sewingalot (Oct 12, 2008)

Jeremy,

Your tank is outstanding!!! Wow. Come over to my house and fix my tanks?


----------



## KDahlin (Mar 12, 2007)

Wö£fëñxXx said:


> _Why_ do you have GDA in "all" of your tanks?
> 
> I don't have GDA in any of mine, does this mean I should have it also?
> 
> What is your conclusion?


I don't know why I have GDA in all my tanks. That's what I'm trying to figure out. Something is off but I don't know what it is. You had said you've never seen GDA in a low light tank, I have it in my 1.5 wpg compact Fluorescent non-CO2 tank. So light isn't all there is to it.

The GDA is only really an eyesore in one tank, that's my 55g with 108 wpg T5HO light. It's growing on the plants which I can't just scrub off. I'm experimenting with increasing the CO2 in this tank.


----------



## i4x4nMore (Mar 31, 2008)

sewingalot said:


> Jeremy, Your tank is outstanding!!! Wow. Come over to my house and fix my tanks?


I would love to work with other people, in person, on their tanks.... especially if the tanks are in dire need of "fixing". Nothing like getting your hands wet and getting to the root of the problem.

Unfortunately, WV is pretty far for us to hang out together.


----------



## jaidexl (Sep 18, 2006)

KDahlin said:


> I don't know why I have GDA in all my tanks. That's what I'm trying to figure out. Something is off but I don't know what it is. You had said you've never seen GDA in a low light tank, I have it in my 1.5 wpg compact Fluorescent non-CO2 tank. So light isn't all there is to it.
> 
> The GDA is only really an eyesore in one tank, that's my 55g with 108 wpg T5HO light. It's growing on the plants which I can't just scrub off. I'm experimenting with increasing the CO2 in this tank.


Considering your lights may be exceedingly efficient, especially the T5HO, and the fact that watts per gallon doesn't really mean anything, I'd say your probably right at the lower limit for GDA. In my experience anyway. 

On a 65gl, I cut down from 192w pc to 96w pc and still had GDA coming back. I switched to a T5HO 4 x 39w and stepped down one bulb at a time with a GDA cleaning between each change, it didn't stop coming back till I got to one bulb, then stepped back up to 2 bulbs (78w) after it was gone and all is good, so far. I did, however, have a lot of CO2 going for most of that experience, then no injection once I got down to one bulb. I'm still not even sure if CO2 has anything to do with GDA, I'm somewhat convince light is the main factor and any amount of CO2 may not have any effect. Although, I've never tried multiple experiments like some folks have, just that one tank, and that's the conclusion I came to after a year of battle. That's not to say one can't pump heavy amounts of light in and never see GDA, I did it just fine for over a year on the same tank, there are obviously some other factors that can bring it on, whatever the situation may be.


----------



## sewingalot (Oct 12, 2008)

i4x4nMore said:


> I would love to work with other people, in person, on their tanks.... especially if the tanks are in dire need of "fixing". Nothing like getting your hands wet and getting to the root of the problem.
> 
> Unfortunately, WV is pretty far for us to hang out together.


Well...if you ever move, we will be pals! My husband keeps wishing I would find a "planted tank" buddy and quit talking to him about KNO3 and its affect on plants, lol! :redface:


----------



## KDahlin (Mar 12, 2007)

jaidexl said:


> Considering your lights may be exceedingly efficient, especially the T5HO, and the fact that watts per gallon doesn't really mean anything, I'd say your probably right at the lower limit for GDA. In my experience anyway.
> 
> On a 65gl, I cut down from 192w pc to 96w pc and still had GDA coming back. I switched to a T5HO 4 x 39w and stepped down one bulb at a time with a GDA cleaning between each change, it didn't stop coming back till I got to one bulb, then stepped back up to 2 bulbs (78w) after it was gone and all is good, so far. I did, however, have a lot of CO2 going for most of that experience, then no injection once I got down to one bulb. I'm still not even sure if CO2 has anything to do with GDA, I'm somewhat convince light is the main factor and any amount of CO2 may not have any effect. Although, I've never tried multiple experiments like some folks have, just that one tank, and that's the conclusion I came to after a year of battle. That's not to say one can't pump heavy amounts of light in and never see GDA, I did it just fine for over a year on the same tank, there are obviously some other factors that can bring it on, whatever the situation may be.


Well, since I already upped the CO2 I'll watch the tank for a week or two. If I don't see any improvement I'll try raising the light some as well as cut back the photoperiod.

Thanks


----------



## niccomau (Nov 3, 2005)

... I'm so confused. I've been reading quite a few threads on algae and I have what I think are Diatoms. People have said that Diatoms feed off silicates and to get rid of it: remove the silicates and up the lightning. I started out with a 30watt light over a 46gal bowfront...the tank has now been set up since Nov 1, 2008. I have sand substrate, so the silicates could have been from that. But I've done enough water changes since then (1 per week) that if the silicates weren't in the tap water it should be gone. So i figured the only thing left to do was up the lighting wattage. So I revamped the tank, scrubbed it clean, and got my lighting to 2 watts per gallon. The algae blew up! It started spreading faster covering my crypts and java fern too (where as it only covered the anubias, and rock structures before). Now the algae is actually hard to scrub off the rocks and plants, though it doesn't really grow on the glass. I'm starting to wonder if it could be GDA, as some parts are beginning to tinge a little green. The tank is very low tech, no added ferts, only low light loving plants like crypts, java fern, anubias, and a couple of apons. The rootfeeding plants are getting some Flourish Root tabs. I am keeping african cichlids, the pH is high 8.0, and the nitrates are virtually non existant (2.5ppm when I overfeed). I put in an order for 24 Olive Nerites, and hopefully they will get this problem in check. If they eat the algae voraciously enough, I'll put the higher lighting on so they don't starve. Other than these steps I've already taken, I'm at a loss of what to do next.:frown: Sorry if I hijacked this thread... but with so many experts weighing in I though someone might be able to hand down some sound advice.


----------



## jaidexl (Sep 18, 2006)

Funny you say that, for the first few months of my GDA battle, I was convinced it was brown diatoms. Brown was covering my leaves and blotching the glass, I might have noticed a touch of green a few times and passed it off as some GSA along for the ride. When the glass turned into a solid sheet of bright green, and it wasted away to the same brown splotches I was seeing for months, I knew it was GDA.

If there's brown on the glass, look at the inside of the front glass from the side of the tank, and see if there's a green coating on it. GDA is more visible from the side rather than looking straight through the glass.


----------



## MarkMc (Apr 27, 2007)

I don't have a severe GDA problem but let me offer these observations based on the last 3 weeks. The amount of GDA in my 55 gallon had increased recently and have been positively affected by a few changes I've made. First increasing the rate of CO2, second installing a circulating power head and lastly installing a more powerful pump on my CO2 reactor. IMO you just can't stress enough the importance of MORE CO2 and EVEN distribution of it in the tank. It's not a minor thing-it's key IMHO.


----------



## plantbrain (Dec 15, 2003)

MarkMc said:


> I don't have a severe GDA problem but let me offer these observations based on the last 3 weeks. The amount of GDA in my 55 gallon had increased recently and have been positively affected by a few changes I've made. First increasing the rate of CO2, second installing a circulating power head and lastly installing a more powerful pump on my CO2 reactor. IMO you just can't stress enough the importance of MORE CO2 and EVEN distribution of it in the tank. It's not a minor thing-it's key IMHO.


I've been telling folks this for about.......10-12 years?
Some still think I'm nuts.

Light factors in..........dosing is pretty far down the list.

For some reasons, I rarely ever have issues with any algae, even with rich sediment ferts, rich water column dosing, sporadic water change routines(I'm gone a lot), large fish loads etc............

And when I do.........it's still CO2.

If CO2 does not work for a client etc, I reduce the light and raise it up, or screen the light. This has been the same old thing for decades now. 
I had 2 tanks with, and 3 without GDA, but it went away pretty well on it's own once I took better care and was consistent.

But the nutrients/light/sediment , dosign etc was about as identical as anyone could do.

The main variable was CO2.

Correcting CO2 will not eliminate some species. But it'll go a long way to solving new growth and beating it back good. Some picking on the algae, blackouts, Excel, waiting for it to do it's life cycle, then nailing it when it's at the weakest point, seems to help.

I do these same things for aquatic weed control.
We nail the weeds when they are at their most susceptible and with several methods, not just one.

"Many little hammers" beating the weed/pest, killing it, hurting it etc.

Regards, 
Tom Barr


----------



## honor (Apr 8, 2008)

i like gda. it makes your tank look more natural. just wipe it off your glass before it really settles in to the micro imperfections of the glass.


----------



## Homer_Simpson (May 10, 2007)

honor said:


> i like gda. it makes your tank look more natural. *just wipe it off your glass *before it really settles in to the micro imperfections of the glass.


It depends at what stage it is at, but GDA is not always easily wiped off, sometimes you have to scrape it off with a credit card using a lot of elbow grease. And if you happen to get GDA that gets caked on like hard water stains on an acrylic tank, good luck trying to scrape it off without scratching your tank. A far as it making the tank look more natural, when I had it, I couldn't even see through the tank to enjoy the plants or fish. It was a real eyesore but I found a fix, LOL :icon_evil :icon_twis


----------



## KDahlin (Mar 12, 2007)

honor said:


> i like gda. it makes your tank look more natural. just wipe it off your glass before it really settles in to the micro imperfections of the glass.


Natural if you're talking about the look of a pond covered with pond scum. Don't know why you'd want that in your house though.


----------



## Floyd R Turbo (Apr 24, 2009)

I've got a 55g with from what I can tell about 4 different kinds of algae. It started with brown diatom, which coated all the plants and driftwood, rainbow rock, lift tubes (getting rid of UGF, just got canister yesterday). Then I started to get green spot algae, and from what I can tell, GDA, which comes back within a week of scraping. I run a Magnum 330 for a few hours after scraping to filter out all the algae floating around in the water, and it just comes right back 2 weeks later. My livebearers much on it all the time, so I leave the back alone and just scrape the front and sides. I also have some (can't remember name) brown hair/spongey like algae growing off the power heads.

I thought the high phosphates (>5.0 ppm in my tank, due to city water issues) cause algae problems, is that not true? I was considering putting phos-zorb in the filter to get them down to nominal levels.


----------



## honor (Apr 8, 2008)

i was talking about the gda taking hold on stuff inside your tank, not on the glass/arcylic, you should clean that imo.


----------

