Wanted: A reliable CO2 system for large planted tanks

Tom Barr

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Jan 23, 2005
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wolfewill said:
I appreciate the suggestion for a diy with a water filter. I’m sure they work but I want one that’ purpose built and a sold as such. And you say to keep it and the canister filter clean is important, and that’s valuable advise. I’ll make sure to do that.

Tell you what, I'll make one for you, charge you 2x as much as it cost me and guarantee it for life.


Still interested? Cause that's all anyone else is going to do.


I use to make them commercially for about 3-4 years. I might know a thing or two or three or four about it.

And you said: ‘You can/should use a relative pH drop to measure the CO2'


This is interesting. I’ve heard that a 0.5 pH unit drop is enough,

I'm much more the type that will tell you what you need to hear, not what you want to hear. I'd run elsewhere fast if I heard this advice above.

but the higher value makes sense for a high light set up; and yes, I do want a [CO2] of 30 ppm or more. So this is something I will set up today. I have two Giesemann 150w MH, two TMC 1500 LEDs, four TMC 600 LEDs and two 24" HO T5 Coralife Colormax (soon to be 4). I’m trying to find a place between a medium lighted tank and high light. I’m not going to have high light demanding plants in the long run.

So use moderate light then given your goal, more light is not "BETTER". Lower light and cooler temps= easier CO2 management.

As for ADA buffering for a long time, our tap water hardness here in Ottawa is very soft - 6 to 7 degrees TH. So the buffering capacity goes a long way. I’ve had Africana in a 90 gallon for 27 months and there is still considerable buffering. The pH would end up in the low 7s over night here without the ADA substrate (in Fluval and Flourite), but remains in the low 6s still.

I do not think you understand the issue there, KH, the alkalinity, is the factor in this and if you do much water changes(what % and frequency do you do?), I have near glacier melt water here, the KH is 1 degree, about 20 ppm. And the % water changes also play a role. The pH is not affected much, if any, at this point on any of my tanks. Not that it matters much since it is relative anyway, but you can degas a tank easily and then measure a again and have another base line to measure the pH relative drop you need to hit a target CO2 ppm.


6-7 degree's TH is not that soft really compared to my tap.


Mine is about 2.


TH is the same as dGH, or general hardness. It is NOT the KH or alkalinity, that buffers the pH. Sometimes there are other things other than bicarbonate that affects the alkalinity, but that's another conversation and one reason to use relative pH drop instead of absolute.

As for a GH booster: Out of the tap the GH is 3 degrees here. So I buffer to a minimum of 4 (4 to 6 being the sweet spot). Do you think this is high enough? I don’t buffer KH at all and it stays ≤1.0 (that’s the Africana at work). And I’m using Seachem Equilibrium. Shouldn’t that do the job? I also use locally supplied dry fertilizers from hydoponics suppliers (potassium nitrate and mono potassium phosphate) plus Seachem Flourish Comprehensive and CSM+B. And, yes I use petalphile and APCs fertilator sites to determine the quantities of each.

Seachem Eq is a bit pricy.


The hydroponic place sells gypsum.


They also sell Epsom salt, MgSO4.


They also sell K2SO4, potash of sulfur.


Buy three 25KG bags of each, mix in equal parts, now you have spent maybe 75$, but have 75kg supply and likely a lifetime's worth of GH booster.


CMS+B, the only thing you might add to that is DTPA 330 sequestrene(Ebay etc), maybe 1 part that to 3 parts CMS+B. 2-5 kg bag will also last a lifetime.


Now the chemicals are nearly free over time.


Use a decent pH meter to measure and monitor pH, use say a Lamotte alkalinity test kit for KH.


For GH addition, you might add 1 table spoon per 60 Gallons of aquarium once a week, post water change.


Should cover everything you need.
 

wolfewill

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Dec 5, 2010
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Ottawa, Canada
Tom Barr said:
I do not think you understand the issue there, KH, the alkalinity, is the factor in this and if you do much water changes (what % and frequency do you do?) TH is the same as dGH, or general hardness. It is NOT the KH or alkalinity, that buffers the pH. Sometimes there are other things other than bicarbonate that affects the alkalinity, but that's another conversation and one reason to use relative pH drop instead of absolute.

Are you suggesting to buffer to a specific TH, or, is that issue moot due to the other additives? When I first started using Africana, The ADA advise was to add baking soda daily to keep the TH at above a minimum of 2 degrees (ref.: Frank Wazeter at that time, and the ADA dealers in Toronto and Trois Rivieres, circa 2012). The advise from the people in the EU (the UKAPS forum) was that TH is irrelevant if the proper nutrients were available, and their arguments were compelling. The ADA advise changed during the course of these discussions: It was deemed a waste of time and had no impact on plant or fish health. So I stopped with no apparent issues. Comments?


I use the PPS dosing strategy and to water changes when required, usually from 2 to 8 weeks in a mature tank.
 
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