# Low light - with C02



## AbbeysDad (Apr 13, 2016)

Don't see why you'd want/need CO2 unless you're gonna do high intensity lights and high ferts.
I think you can have an awesome tank with just medium light, root tabs and (very) modest ferts.


----------



## Axelrodi202 (Jul 29, 2008)

CO2 and low/moderate light works great; many of Amano's scapes were essentially this. Growth isn't as fast as in high tech but is very green and lush.


----------



## SwissCheeseHead (Dec 24, 2014)

CO2 can be beneficial for plant growth even in a low/medium light set up. I'm currently using DIY CO2 in my medium light set up. It's been set up for just under a week and I'm already seeing positive effects. Plants are more perky, and seem to have taken in more rich colors, I've increased my photoperiod from 6 hrs to 7 hrs (which is a benefit in itself in that I can enjoy the tank for longer). You obviously don't need 30 ppm (maximum) but even at 10 ppm, I'm seeing the positives.

I do use the EI method of dosing and supplement with Excel as another carbon source and to keep algae at bay. So far, so good.


----------



## K1963158 (Aug 15, 2016)

@Axelrodi202: That's the goal, not an Amano tank, my skills are nowhere near that but I want healthy plants that make a good environment for my fish.

@SwissCheeseHead: For sure not planning to go for high C02, just want to raise it a bit but most importantly keep it at a consistent level to curb algae growth.


----------



## Hoppy (Dec 24, 2005)

You can use a drop checker to make using CO2 for the first time much less threatening. If you use low to medium light intensity you don't gain that much from using the magic 30 ppm of CO2. But, using around 10 ppm or less still gives you a big improvement in plant growth and health. To achieve this, just use 1 dKH water in the drop checker instead of the usual 4 dKH water. That makes the drop checker color be green at about 10 ppm of CO2, and yellow at about 30 ppm. So, all you have to do is keep the color between green and yellow, very easy to do. If you do this with DIY CO2 you can avoid most of the BBA problems that often come with DIY CO2 by also dosing "Metricide 14 day"(very cheap) at about 1 ml per 10 gallons of tank water. Now, your CO2 will last much longer, your costs will still be low, and your plants will do much better.


----------



## K1963158 (Aug 15, 2016)

AbbeysDad said:


> Don't see why you'd want/need CO2 unless you're gonna do high intensity lights and high ferts.
> I think you can have an awesome tank with just medium light, root tabs and (very) modest ferts.



To keep a consistent level of CO2. In Tom Barr's article (follow da link) he writes how water changes create an inconsistent supply of CO2 and could encourage algae growth. He advises against water changes and just do top ups. I like doing my weekly (or more) water changes so to keep CO2 consistent I plan on supplementing this tank with pressurized CO2.

I'm not going to argue with TB :laugh2:


----------



## jeffkrol (Jun 5, 2013)

http://www.bio-web.dk/ole_pedersen/pdf/PlantedAquaria_2001_2_22.pdf
good read...........


----------



## K1963158 (Aug 15, 2016)

@jeffkrol: "Damn it Jim, I'm an accountant not a scientist!" Said in mock Dr. McKoy voice. LOL Putting aside my attempt at some humour it was a good read and what I got from it is that adding CO2 to a low light environment plants use less energy to obtain CO2 and can use that energy to optimize their light utilization.


----------



## Axelrodi202 (Jul 29, 2008)

K1963158 said:


> @Axelrodi202: That's the goal, not an Amano tank, my skills are nowhere near that but I want healthy plants that make a good environment for my fish.


In terms of plant growth I think this is an attainable goal. If you don't have it already, I'd suggest getting _Nature Aquarium: Complete Works 1985-2009_. You'll see that many of Amano's scapes consisted entirely of hardy, lower-light plants, like moss, Anubias, and ferns. The primary challenges to replicating his work are access to sufficient plants at the beginning and the artistic vision of combining plant and hardscape. It's important to plant heavily from the start, but some of these plants (like Bolbitis for example) aren't always readily available in large quantities due to their slow rate of growth.


----------



## K1963158 (Aug 15, 2016)

As much as I glean stuff from the internet nothing beats having a great book like that for a reference.


----------



## AbbeysDad (Apr 13, 2016)

K1963158 said:


> To keep a consistent level of CO2. In Tom Barr's article (follow da link) he writes how water changes create an inconsistent supply of CO2 and could encourage algae growth. He advises against water changes and just do top ups. I like doing my weekly (or more) water changes so to keep CO2 consistent I plan on supplementing this tank with pressurized CO2.
> 
> I'm not going to argue with TB :laugh2:


Tom also wrote "CO2 is a bit like a drug addiction that hobbyists get hooked on." :laugh2:
Well, not really arguing, but I don't have CO2 (or Excel), do weekly water changes, and in addition to two filters circulating water, I even have a bubble bar streaming bubbles 24/7...I use root tabs but dose very little ferts and the plants are doing really well.
But then I pre-filter my water for water changes and it sits in 5g pails for days or even weeks sometimes so CO2 is likely negated....and/or the bubble bar would likely quickly equalize and balance O2 and CO2.
But it's just been 3 months so who knows.

footnote: The jungle val in the rear was set back after I followed some bad advice and cut it back to 2" supposedly for it to come in thicker - big mistake, but I planted more and it's coming along.


----------



## burr740 (Feb 19, 2014)

AbbeysDad said:


> Tom also wrote "CO2 is a bit like a drug addiction that hobbyists get hooked on." :laugh2:
> Well, not really arguing, but I don't have CO2 (or Excel), do weekly water changes, and in addition to two filters circulating water, I even have a bubble bar streaming bubbles 24/7...I use root tabs but dose very little ferts and the plants are doing really well.
> But then I pre-filter my water for water changes and it sits in 5g pails for days or even weeks sometimes so CO2 is likely negated....and/or the bubble bar would likely quickly equalize and balance O2 and CO2.
> But it's just been 3 months so who knows.
> ...


Your tank looks very nice. 

Nobody is saying CO2 is necessary for a low light tank with non demanding plants. But there's no debating that CO2 is a huge help to such a tank.


----------



## K1963158 (Aug 15, 2016)

AbbeysDad said:


> Tom also wrote "CO2 is a bit like a drug addiction that hobbyists get hooked on." :laugh2:


LOL about that cuz I had that addiction...started off with DIY then to full blown pressurized high light tank.

I have all the stuff I need to set up a pressurized CO2 system so it's not a big deal for me to do. 

Nice tank btw. your Angelfish look very happy


----------



## AbbeysDad (Apr 13, 2016)

K1963158 said:


> LOL about that cuz I had that addiction...started off with DIY then to full blown pressurized high light tank.
> 
> I have all the stuff I need to set up a pressurized CO2 system so it's not a big deal for me to do.
> 
> Nice tank btw. your Angelfish look very happy


Thanks. 
It seems that CO2 will make your plants grow faster (mine seem to grow fast enough!) and I can see how initially that would help achieve the necessary bio-mass quicker for balance and ward off evil algae....and since you already have the equipment, why not use it? I'd think after a time you might want to cut back the amount unless you want to do weekly trimming and replanting.


----------



## K1963158 (Aug 15, 2016)

AbbeysDad said:


> Thanks.
> It seems that CO2 will make your plants grow faster (mine seem to grow fast enough!) and I can see how initially that would help achieve the necessary bio-mass quicker for balance and ward off evil algae....and since you already have the equipment, why not use it? I'd think after a time you might want to cut back the amount unless you want to do weekly trimming and replanting.


I might do that once the tank has settled and is in balance. I have another tank ( 50 gallon'ish) that has been running for over 5 years, started with CO2/medium light, then to CO2/high light.....now is at low light with no CO2 (dosing Excel though) and is doing fine.

I started this thread just to get input from other peoples experience with low light/CO2. Wanting to know about their algae issues, what kind of plants were successful for them etc. Hopefully turning out to be a good read for others to learn from.


----------



## sdbrewer (May 17, 2012)

My experience with low light and CO2 has been great. It's worth mentioning I dose macros and micros when I do a water change.

My anubias arrived with a lot of algae on. I hacked most of the leaves away on otherwise healthy rhizomes. During the first couple of months I used excel to work away at any remaining algae.

My previous tanks have either been low light/no CO2 and showed slow, stagnant growth, or have been high light/CO2 and too much maintenance to keep up with in the long term. My current tank has been a much more enjoyable experience.

It wasn't my intent to show a perfect timeline when taking these pics, so they only show the general growth of the tank over time.

April 5, 2016
https://goo.gl/photos/M2vgSx9QLodtBn8PA

May 18, 2016
https://goo.gl/photos/arh9XuXjpBzYT3Ls8

July 25, 2016
https://goo.gl/photos/Vx8wTvfpFQbAJmt87

August 4th, 2016
https://goo.gl/photos/GR1RhMDMEYxGRqMe6


----------



## K1963158 (Aug 15, 2016)

sdbrewer said:


> My experience with low light and CO2 has been great. It's worth mentioning I dose macros and micros when I do a water change.
> 
> My anubias arrived with a lot of algae on. I hacked most of the leaves away on otherwise healthy rhizomes. During the first couple of months I used excel to work away at any remaining algae.
> 
> ...



Beautiful tank! Thanks for sharing. I have a big supply of dry ferts from my high light/high CO2 days so I will plan on dosing the tank as well.

What do you estimate your PAR to be?


----------



## sdbrewer (May 17, 2012)

K1963158 said:


> Beautiful tank! Thanks for sharing. I have a big supply of dry ferts from my high light/high CO2 days so I will plan on dosing the tank as well.
> 
> What do you estimate your PAR to be?


Thanks.

I avoided adding the ferts when I first set up the tank, but I noticed the first set of anubias leaves to grow in developed pin-holes. I began adding ferts after that and the issue went away.

From my understanding, I have about 25 PAR at the substrate.


----------



## Hoppy (Dec 24, 2005)

*The Argument for DIY CO2 for Low Light tanks*

Thanks to member "hard determinist" (in http://www.plantedtank.net/forums/1...72153-gassed-my-fish-today-2.html#post9474098) I now have access to Ole Pedersen's scientific paper that describes the study done for Tropica about the benefit of CO2 to aquatic plants. Studying this paper shows us the great benefit we get from CO2, at very low levels, in our low tech (low light) tanks.

The study described in the paper concerned the relationship between plant growth rate, or at least Riccia growth rate, vs light intensity and CO2 concentration in the water. This was not intended to show that we need CO2 in our low light tanks, but the data in the report certainly shows that CO2 would be a great addition to those tanks.

Using that data I made this chart:









The chart shows the relative growth rate of Riccia in a 25 PAR (very low light) tank at different concentrations of CO2. The growth rate is expressed as the ratio of growth rate at a given ppm of CO2 divided by the growth rate at 3 ppm. The 3 data points used to generate that chart were for CO2 levels of 0.7 ppm, 6.6 ppm and 35 ppm. The most interesting thing is that as little as 8 ppm of CO2 gives you more than 3 times the growth rate that atmospheric CO2 (3 ppm) alone gives you! And, as little as just over 4 ppm doubles the growth rate that atmospheric CO2 gives you. Even a 2 liter DIY yeast or citric acid based CO2 generator can give you more than that in pretty large tanks.

The reason this is so great is that algae problems generally get much, much worse as you increase the light intensity, but that small an addition of CO2 to the tank does very little to encourage algae to start growing. So, if your low tech tank is disappointing you by just barely growing plants, you don't need to risk big algae problems by buying a brighter light, you can add a little DIY CO2 and get an even bigger improvement with no more algae woes than you already have.

DIY yeast generator CO2 systems are still low tech. They take little more attention than you already give your tank. One problem with DIY CO2 is the fluctuating output they provide, but you can dose Excel or Metricide 14 Day at just 1 ml per 10 gallons of water, and that tends to prevent the fluctuations from triggering algae attacks.

I have a 65 gallon tank, not a giant tank, but much bigger than 10 gallon tanks, and the common advice we get says that you need pressurized CO2 to do any good for that size tank. I have been using DIY CO2 on that tank for over a month now. This is after trying for over a year to get the attractive plants I like to look at, but with low light, so I won't get frustrated by algae. I have had little to no algae, but my plants have grown so slowly the tank hasn't really satisfied me. With the DIY CO2 at about a bubble per second of CO2 - very low for that size tank - my plants are looking much better, and are growing fast enough that I now prune them weekly. This is with about 30-35 PAR lighting, which I had increased from my original about 25 PAR to try to encourage some plant growth to occur. So, the chart above is accurate, not just a quirk in the data.

DIY CO2 is a 1980 phenomena if not even older. But, for our low tech (low light) tanks it should become the latest thing!


----------



## K1963158 (Aug 15, 2016)

All this feedback is very encouraging to me, soon I will be starting my tank and I really want to avoid algae in such a deep tank. I'm guessing that I will have about 35+ PAR directly under my light fixture so I hope to get adequate growth. 
@Hoppy: I will for sure use your hing regarding the drop checker and the 1dkH solution to get 10ppm of CO2. That was a useful hint.
@sdbrewer: Amazing growth at such low light.


----------



## AbbeysDad (Apr 13, 2016)

Hoppy said:


> DIY CO2 is a 1980 phenomena if not even older. But, for our low tech (low light) tanks it should become the latest thing!


So Hoppy, is your DIY CO2 yeast and sugar or citric acid and baking soda? If yeast, is it bakers or brewers? Are you just dispensing through an air stone or some other means? Finally, are you somehow only dispensing during 'light' hours or 24/7?


----------



## Hoppy (Dec 24, 2005)

AbbeysDad said:


> So Hoppy, is your DIY CO2 yeast and sugar or citric acid and baking soda? If yeast, is it bakers or brewers? Are you just dispensing through an air stone or some other means? Finally, are you somehow only dispensing during 'light' hours or 24/7?


I started with bread machine yeast/sugar, trying a new method to see if I could shut it off when the lights were off, and save the CO2 instead of wasting it. That didn't work out very well. So, I switched to citric acid/baking soda, which I am still using. I shut it off with a solenoid valve when the lights are off. I use the same timer that controls the lights, and have had various problems getting the CO2 to restart when it is turned on. Some days I didn't get the CO2 to come on until midday. But, I still get the benefit, and no algae attacks.

I use a Hagen Elite mini internal filter (a tiny powerhead with an attached filter cavity) with the CO2 hose stuck into the filter cavity instead of the filter sponge. I have a check valve right at that end of the CO2 hose. I started with the check valve at the generator, in the stand under the tank. That let water creep down the hose when the CO2 was off, which greatly delayed the restart of CO2 flow. Then I moved the check valve to the rim of the tank, which helped, but still let water creep up to the rim, slowing the restart of CO2. So, now I have the check valve right at the Hagen Elite filter chamber, but then the CO2 hose kinked at the "U" turn at the check valve, which tended to stop the CO2 flow entirely. Yesterday I made a "U" fitting from two "T" fittings and used that to eliminate the kinking. I am describing this to show that even with all of those intermittent stoppages of CO2, I'm still getting the benefit of adding CO2.

As that chart shows, it takes only a little CO2 to get most of the benefit of CO2 when you have low light. I think, if I started over, I would just use a 2L bottle of yeast/sugar and let it run continuously.


----------



## sdbrewer (May 17, 2012)

K1963158 said:


> I'm starting a 90'ish gallon tank and want it to be low maintenance in the sense that I want:
> 
> 
> thriving plant growth but want to keep my hands out of the tank
> ...


These goals are completely attainable with low light and CO2.

In my experience:


I intend to do a water change every week, but it's more like every second week, and sometimes every third... Plants keep on growing either way. I haven't trimmed my tank yet, but the carpet is probably due for one.
I dose ferts when I change the water. And again if I think it's been a week or so. And again if it's been another week...
If I'm procrastinating on changing the water, it's not unusual to get some algae growth on the glass of the tank. That's my cue to scrape the glass and do a water change. I wait to do it on my day off.
A larger window of time to react and less damage, if any, is a huge benefit of this set up. Mind you, I'm referring to my 7.13 gallon tank. I imagine your 90 gallon would be more forgiving.


----------



## K1963158 (Aug 15, 2016)

@sdbrewer: Thanks for sharing, that's exactly what I'm hoping for as well.


----------

