Getting the CO2 Right Changed Everything

[Philosophos]

I'm posting this mainly because of how many hours I spent working on fertilization, to the point of severely over-focusing. I've found a lot of concentration on nutrients besides CO2 when it comes to keeping a balanced aquarium. If this post saves another person even an hour of headache, then it will not have been a waste of my time.

So after what has been months now of fighting with an assortment of algae, things have finally turned around. I tried cranking up the CO2 at first; it was free-flowing through the diffuser. Nothing. I altered ferts and light schedule, and still nothing. Because I enjoy catching and eating fish when I'm not keeping them, I ended up out camping. The day before my fiance did a water change, fed the fish a massive helping of black worms, cleaned a very dirty CO2 diffuser, and then left. no fert dosing or water changes happened for the week after, with an over night stop-in between camp sites to feed the fish and shower. Normally treatment like this has very consistently resulted in massive algae growth. I was fearing the worst when I got back.

7 day later the HC looked healthier than ever; it had out-competed the BBA that not even 8ml/day of spot treated flourish in 65L could take care of. The worst of it was some magnesium deficiency in the L. repens, which looks to be a few inches higher despite the deficiency. The cause of this change? One bleached and scrubbed diffuser. The drop checker was more responsive, the bubbles smaller, the distribution far better. If I had done one thing differently with my CO2, which would've taken a fraction the time to troubleshoot, I could've avoided a lot of
frustration.

-Philosophos

 

[rodrigaj]

When I first got into pressurized CO2, I looked into using a glass diffuser. The common wisdom at the time was that they were more trouble than they were worth. I went with an external reactor made by the Japanese company Jaqno. It was exported and sold by M3. To my knowledge this reactor is no longer sold in the US. Here is a picture of it I found on the web.

That was 15 years ago, and the reactor is still part of my system, still doing its thing. I can't even tell you when I last opened it up for cleaning.

I'm not sure why glass diffusers are still being sold. Perhaps its the simpler setup. And... with DIY reactor plans on the web, I'm not sure why folks put up with the headaches of glass diffusers.

 

[Henry Hatch]

I think a lot less about ferts than I used to. My focus now is on co2, circulation and light spread.

I've started playing around with misting again and the early results are encouraging. I built Tom's venturi reactor and am working on a modification to juice it up even more. If it works, I'll post and let folks know.

I'm through worrying about things like iron levels. It never got me anywhere.

 

[Gerryd]

Hi,

Could someone please explain this 'c02' and it's importance to plants? LOL

I've never seen it mentioned or discussed on this site before................

In all seriousness, unstable and insufficient c02 levels have been at the heart of the majority of my algae/plant growth issues.

I have struggled/still struggle with c02 more than any other issue..........

Later,

 

[Philosophos]

Rodrigag, your reactor looks very simple in its design; how even is the distribution? Does the pH alter from one side of the aquarium to the other by much? In my case I'm using a diffuser for now because a good CO2 reactor is something I have to order in, and I haven't gotten anything shipped to me from a place that supplies hardware in a while. Usually there's discounts for large orders, so I try to do it that way. Getting good planted aquarium equipment here isn't easy; I get looks like I'm insane when I talk to the LFS owners around here about high tech planted aquariums. For now, I'm getting the CO2 I need. It wouldn't have been much work to clean it if I hadn't left it for something like 4-6 months

I've read that the difference between diffuser and reactor is negligible when it comes to dispersion. Personally, i'd like to get the ugly line out of the tank, and maybe the heater. I think they're still sold because they're cheap, and there's no such thing as in-line with HOB trickle filters.

Henry, I agree with the light spread thing. T5's get more tempting by the day for that very reason. As for nutrients, right now it seems that deficiencies show before algae can take over. If this is how things usually go, planted aquariums aren't looking so hard anymore. Speaking of which, does anyone here find ludwigia shows magnesium deficiencies easily? I'm dosing MgSO4.7H2O pretty high at times, but it still shows.

Gerryd, CO2 is the carbon source for plants. Nearly all life on earth is carbon-based (aside from some obscure bacteria and such), plants happen to get theirs as a gas. Photosynthesis causes carbon fixation; in simple terms, it kicks off the O2 and retains the carbon for things like cellular structure. Co2 being lighter than air, and also relatively inert, doesn't tend to want to stay in the water. Diffusing it works like any emulsion; ever made hollandaise? Same idea.

-Philosophos

 

[Gerryd]

Philosophos,

I understand what c02 is and it's importance. I was being sarcastic.

Guess that didn't come through............

 

[Philosophos]

Crap. My sarcas-o-meter has been borked again

I'm reading too fast, with too little sleep I think... it's easier to scan fast then type while resting eyes, followed by spell-check.


-Philosophos

 

[Henry Hatch]

Actually t5's are a problem with respect to light spread because the fixtures are quite narrow. I like to raise the height of the fixture to improve the spread.

I wonder sometimes if the distribution of co2 may be as important as the amount of co2 in the tank. I keep thinking about the thread on the ADA aqua forest tanks. They grow plants in low light that I would not think is possible. Could it be that when we raise the co2 levels in our tanks that what we are doing is making up for poor circulation and when we get better circulation we may actually need less co2 ( lower levels ? ) to get good plant growth ?

 

[Tom Barr]

I'm posting this mainly because of how many hours I spent working on fertilization, to the point of severely over-focusing. I've found a lot of concentration on nutrients besides CO2 when it comes to keeping a balanced aquarium. If this post saves another person even an hour of headache, then it will not have been a waste of my time.

So after what has been months now of fighting with an assortment of algae, things have finally turned around. I tried cranking up the CO2 at first; it was free-flowing through the diffuser. Nothing. I altered ferts and light schedule, and still nothing. Because I enjoy catching and eating fish when I'm not keeping them, I ended up out camping. The day before my fiance did a water change, fed the fish a massive helping of black worms, cleaned a very dirty CO2 diffuser, and then left. no fert dosing or water changes happened for the week after, with an over night stop-in between camp sites to feed the fish and shower. Normally treatment like this has very consistently resulted in massive algae growth. I was fearing the worst when I got back.

7 day later the HC looked healthier than ever; it had out-competed the BBA that not even 8ml/day of spot treated flourish in 65L could take care of. The worst of it was some magnesium deficiency in the L. repens, which looks to be a few inches higher despite the deficiency. The cause of this change? One bleached and scrubbed diffuser. The drop checker was more responsive, the bubbles smaller, the distribution far better. If I had done one thing differently with my CO2, which would've taken a fraction the time to troubleshoot, I could've avoided a lot of
frustration.

-Philosophos

Welcome to the club
Maybe 90% of folks go down this path.

This is one really good point for using sediment rich nutrient sources like MS, ADA AS etc......they focus less on all of that and more on CO2.
They do a little water column, but it's less critical and much less the focus.

Coming to terms with dosing locations and sources is still a rather easy thing.....
it still boils down much more to CO2/good light , good spread, good CO2/current distribution etc.

But many go too far with ferts, or locations in one spot, and rarely enough with good CO2.

Not everyone hits good CO2............so they keep messing with ferts and eventually hit a limiting factor that reduces the CO2 demand so they think it's nutrients that are the key.

No amount of obvious results, explaining will convince them otherwise.
Some never hit good CO2 and then think their tank is "special".
So it's easier for many to blame nutrients for 90% of their issues, when 90-95% is the CO2.

Same is true for algae issues.
They are so rare when the CO2 is addressed.........

I have made more reactors than I can count over the years, decades now.......
I tried mazzei's, needle wheels(I'll be doing more later with those shortly), and have mostly disc right now.

Why do I try each type and have several times back and forth?

I want to learn more about the practical issues, I see folks with problems and I'd like to know more about where we can go wrong, this means I can help and pinpoint issues folks have with several CO2 dosing methods, not just one.
Same with nutrients/dosing methods, sediment,s filters, fish, plant species etc.

Maybe I overlooked things the first time 8 years ago, I know more today than I did back then etc, we learn and get better, so we can better evaluate the method later as our skill level and observational power increases.

I use Tilex on the disc when I do the water change maybe once every month or so. I want nice fine bubbles all the time.

This means more maintenance. A trade off.
The disc also have micro bubbles all over, just like mazzei and needle wheel, so there's no gain there.

Reactors general dissolve the gas entirely.....but are very low maintenance. Good points for both.

I like the CO2 mist however, it does seem to improve the growth.
So this is an aesthetics issue, one that ADA seems alright with also.

A simple hand on external needle wheel, a smaller one, say 200gph for a 55 gal or smaller, to about 300-400gph for 100 gallon tank ought to do the trick.

This is the next project I have coming up.

But if you'd never seen the difference with good CO2 vs not, you might never be aware of the impact this has..........it's really surprising how many have not.

CO2 is never on any of those plant deficiency tables..........wonder why? Those are from terrestrial and emergent studies, not submersed.

Regards
Tom Barr

 

[Philosophos]

Actually t5's are a problem with respect to light spread because the fixtures are quite narrow. I like to raise the height of the fixture to improve the spread.

One T5 is a problem, but they can be had in lower wattage than a CF (65w vs 14w), so I was thinking 3-4 strips front to back with independent mounts. The idea is that it would allow me to shuffle each one back and forth for better distribution.

I wonder sometimes if the distribution of co2 may be as important as the amount of co2 in the tank. I keep thinking about the thread on the ADA aqua forest tanks. They grow plants in low light that I would not think is possible. Could it be that when we raise the co2 levels in our tanks that what we are doing is making up for poor circulation and when we get better circulation we may actually need less co2 ( lower levels ? ) to get good plant growth ?

From my experience with a plugged diffuser stone, I'd say distribution is definitely important, but not necessarily a core problem to the hobby. The bubbles were larger, and going straight up; the area around the diffuser was doing well, but the rest of the aquarium was looking nasty. Now things are distributing fine; tiny bubbles everywhere, and no meaningful variance between the left and right side of the tank according to my pH meter. On the other hand, I run filtration at a rate of about 12-14gph/gal.

I use Tilex on the disc when I do the water change maybe once every month or so. I want nice fine bubbles all the time.

This means more maintenance. A trade off.
The disc also have micro bubbles all over, just like mazzei and needle wheel, so there's no gain there.[/quote]

I tried tilex; it didn't work for me this time due to the level of neglect. I had to bleach soak the entire disk, followed by a couple rinsing methods. Next time I clean it, I'll give the tilex a try again.

I managed to clean the disc off with maybe 5 minutes of active involvement; not bad considering how long a full trimming and water change takes.

Reactors general dissolve the gas entirely.....but are very low maintenance. Good points for both.

I like the CO2 mist however, it does seem to improve the growth.
So this is an aesthetics issue, one that ADA seems alright with also.

A simple hand on external needle wheel, a smaller one, say 200gph for a 55 gal or smaller, to about 300-400gph for 100 gallon tank ought to do the trick.

This is the next project I have coming up.

Needle wheels look interesting. Does it damage canister filters to bubble the CO2 into the intake? If not, the impeller on a canister could be modified in to a needle wheel. I think if the mist were gone, I'd miss it. I like being able to see that things are properly diffused and distributed. Needle wheels sound like a very good idea; I'm going to go poke around at a LFS that carries spare parts.

-Philosophos

 

[mi5haha]

Needle wheels look interesting. Does it damage canister filters to bubble the CO2 into the intake? If not, the impeller on a canister could be modified in to a needle wheel. I think if the mist were gone, I'd miss it. I like being able to see that things are properly diffused and distributed. Needle wheels sound like a very good idea; I'm going to go poke around at a LFS that carries spare parts.

-Philosophos[/QUOTE]

So far have not seen any needle wheel modified canisters yet. It may still be difficult to guide the Co2 pipe down to the water inlet beneath the pump (not the water inlet of the canister), so it will require a hole either on the cap or on the body of the canister, and also something which can mount the Co2 pipe there (in this way, Co2 bubbles will not go through filtering materials inside the canister).

Also the pump in the canister should be powerful enough so its DIY needle wheel blades can chop Co2 bubbles.

I tried smaller powerheads. Less than 5W, the bubbles are much bigger. 6W power head can do the job (looks like a threshold) and 10W needle wheel (not needle brush type, that type is too powerful for small tanks) pump (around 800Liter per hour) is much better with less chopping noise.

 

[rodrigaj]

Rodrigag, your reactor looks very simple in its design; how even is the distribution? Does the pH alter from one side of the aquarium to the other by much?

I don't test, I let the plants and fish tell me if I have it right.

I have a very large pump for my tank, which allows me to divert the reactor output to the bottom of the tank via PVC and run another PVC output along the top. I look for plant movement to let me know if all parts of the tank are getting CO2. I look to see if the fish are stressed to tell if I have too much CO2.

Once set up, there is no more need for adjustments.

 

[VaughnH]

I would be very reluctant to modify a canister filter pump to make it more of a needle wheel type, because that will always reduce the flow rate, and probably the output head for the pump. Canisters, in my opinion, need all of their pump capacity they can get.

But, putting a needle wheel pump in the output line from the canister seems like it might work very well. I might consider trying that sometime in the future when I get bored with my RFUG system.

 

[Philosophos]

It sounds like an aquatic plant oriented company needs to do a little work with a good hardware manufacturer. Creating a canister designed to also function as a diffuser would probably work well. I can't believe how low energy demand some of these pumps are; I don't think anybody would complain about a few more watts on the power bill.

-Philosophos

 

[Tom Barr]

Well, 2-5$ more a month can add up for some.
15-20 watts adds up.

I'd like a simple Hang on the Back needle wheel.

Using a small as possible discrete pump, say 250gph or so.
Most are big ugly things, hard to hide.
The other option is an in line loop after the filter, basically a by pass loop and a pump added there with the CO2 input.

Plumbing etc, but should run well.

Never got around to this, the mazzei was chosen instead.
But that's one such option.

Modified mesh impellers are a good DIY solution.
I'll most likely go that route using a maxi jet 1200 and adding mesh to the impeller.

I think if folks are not getting the results they think they should, trying different things with CO2 diffusion really can open their eyes.

Many assume it's just a function of adding more and more CO2 and that's all.
But that's not the 1/2 of it....

rodrigaj has a large pump + good distribution........then lets the eyes do the rest.
Many assume that all CO2 methods are the same, that distribution does not matter much, flow rates do not matter much etc and do not know what awesome good CO2 levels look like without harming their fish.

This leads to issues and they are inexperienced. So some kill their fish, some go very slow to avoid killing their fish, some get lucky sooner than others etc.

Not an easy path, but one I went down myself, I suspect most that do well have also.

Regards,
Tom Barr

 

[detlef]

Creating a canister designed to also function as a diffuser would probably work well. I can't believe how low energy demand some of these pumps are; I don't think anybody would complain about a few more watts on the power bill.

-Philosophos

Well said and very true. That same idea got me one year ago to ask Eheim if they could implement a needle wheel pump in their new series of canisters. Too bad.
NO they replied! They were not interested at all.

Can't believe how stubborn even big companies can be. Or is it the other way round: Being stubborn is typical for big companies!

A strong (but quiet!) canister equipped with inputs for CO2 and O2 right before the needle wheel pump is what I'd desire to buy!!!!

Best regards,
Detlef

 

[Philosophos]

20w can add up, but compared to existing expendature of lighting and heating in even a 10G, it isn't much. I could probably save 480 watt hours by turning out a couple lights more often.

Is 250gph necessary for a strong enough impeller? It sure wouldn't be rig for the smaller aquariums. My pencil fish would be plastered to the side of the glass at a combined 500gph in a 20g. Or will the other head be removed, mostly eliminating the increased filtration rate?

I've found distribution the easier part; my prefference is for relatively high flow rates (8-12gph/gal when I can) and lots of fine mechanical filtration for the sake of cleaner water, even in a sparsely planted aquarium. I think under-filtration is more of a problem than most people realize.

-Philosophos

 

[mi5haha]

Bigger tanks are better. Water flow (let's say a 10W needle wheel pump, 800 Litre/hour) from the needle wheel pump plus the water from the canister (20W, 1000Litre/hour) would be strong.

Either the water flow has to be guided out through a long horizontal spray bar, or it can be guided out through a vertical placed spray bar but with more holes in 180 degrees, so the water would be diverted towards 180 degree directions (broadcast) with more gentle water flow. This would be practical for smaller tanks in which a 10W power head would be powerful enough blow the plants down.

 

[SuperColey1]

One T5 is a problem, but they can be had in lower wattage than a CF (65w vs 14w), so I was thinking 3-4 strips front to back with independent mounts. The idea is that it would allow me to shuffle each one back and forth for better distribution.

You're along the right lines here in that more tubes gives a better spread than 1 tube but T5 means more penetration and intensity not spread. 3 T8s will always be better spread than 2 T5s because of this. more tubes making the same amount of light will mean that the light is spread out better.

This seems to be the reason why LEDs are working so well because you can spread out loads of them all over the hood. It may not necessarily be more actual light but the spread improves PAR imeasureably

With CO2 distribution is much more important than the amount (within reason.) We can pump in 10x X amount with poor distribution and not see as good results as 1x X amount with poor distribution. If there were a way to get even spread I dare say we could reduce to much lower levels with good results. However water and physics mean this is nigh on impossible. Even with reactors much of the CO2 is lost. You don't see it because there are no bubbles but it still gasses off

glass diffusers should really be cleaned weekly to maintain a consistently good bubble size. Mine never gets dirty

I like being able to see that things are properly diffused and distributed.

I agree. You can easily see if plant growth is affecting circulation too or even if the flow is reducing (time for some maintenance.)

AC

 

[Philosophos]

You're along the right lines here in that more tubes gives a better spread than 1 tube but T5 means more penetration and intensity not spread. 3 T8s will always be better spread than 2 T5s because of this. more tubes making the same amount of light will mean that the light is spread out better.

Yes, the intensity is something else that I'd look forward to. I've always got a little haze of diatom algae and some spindly leaves down low; it would be nice to get rid of it all. How does the increased penetration on T5's work? Is it purely by putting out more PAR per watt, or is it something in having different nm of wavelength within PAR?

glass diffusers should really be cleaned weekly to maintain a consistently good bubble size. Mine never gets dirty

Weekly? You notice a difference cleaning that often? I suppose it's not a big deal if you're already doing a trim and water change.

-Philosophos