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CO2 issue seeking second opinion

670 Views 5 Replies 5 Participants Last post by  joeyNdana
I have a 125 gallon planted aquarium that has been running for several weeks after combining a 55 gallon planted tank and a 40 gallon breeder planted tank. The set up is as follows: almost all of substrate from the 55 gallon was used as a base along with used filter media from both tanks, filtration is by a Fluval FX6 and an Aquatop CF500UV, lighting for now is a 48 inch Hagen GLO T5HO suspended some 14 inches above top of tank, CO2 is pressurized via an older Drs. Foster and Smith semi-automatic kit (Azoo regulator), check valve, GLA glass bubble counter, a small glass diffuser aimed into output of Aquatop canister to spread CO2 and a CalAqua 2 bowl drop checker with fairly new fluids from GLA, finally I am also dosing via EI method dry ferts from GLA. Lights and CO2 are on timer from 0900 to 1500 hours daily.
After initial set up the drop checker color on both bowls was nearly the same green color so I had the correct amount of CO2 going into the tank and I have seen some plant growth.
I was recently away for 5 days and when I returned I noticed that the top indicator bowl of the drop checker was completely clear even though no adjustment to the CO2 induction was made. I contacted GLA and they stated that they believed that the problem was contaminated fluids in the drop checker even though I purchased new fluid prior to setting up this tank. I am seeking other opinions to help me get my CO2 dialed back in correctly. Thank you in advance to all responding members - :fish:
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Would be hard I should think, to get CO2 evenly distributed throughout such a large tank with single diffuser.
Might consider plumbing the CO2 line into intake on canister for better distribution out through the spray bar ,which if mounted on back glass ,aimed toward's the front glass,might produce better distribution of CO2 especially as plant growth increases and plant's maybe block flow of CO2 to some area's with just the one diffuser.
Sorry ,can't offer any help regarding fluid in drop checker's.
Thanks roadmaster.
I did have that setup in the 55 gal with the CO2 going directly into the intake of my Aquaclear 110 - had no bubbles and even distribution of CO2. I was going to actually do that method by placing CO2 line into the Fluval FX6 intake strainer but the manual suggested this would hurt filter performance. Guess I could try it and see how it works out as my DIY PVC spray bar is attached to the Fluval. Thanks again.:thumbsup:
I have a 125g and I know for a fact co2 diffusion is a challenge in a volume of water that big. There are a few things you can do. You can add two inline atomizer diffusers to the output of each canister. Or you can add a couple of reactors to the canisters. Or you can add a separate loop with a needle wheel pump dedicated only to co2 diffusion. The first two options require splitting the co2 with two needle valves, and the third does not require splitting. BTW you’re lighting is extremely low intensity given the height you’re suspending the fixture and that it’s only two T5HO bulbs.
My drop checkers turn clear after about 1-2 weeks in the tank. I just assumed it was normal and stopped using them :) I feel more comfortable relying on pH change and monitoring the fish.
I have a 125 gallon too, Orlando from GLA helped me out quite a bit getting mine dialed in. I was using a single diffuser hooked up to the outlet tube, flowing from the corner of the tank. I had a feeling I wasn't getting even distribution, testing the PH and KH method proved that.

First he had me remove the spray bar (I was using the Eheim spray bar). The back pressure of the spray bar limits the circulation, using an open nozzle created the right kind of turbulence to circulate the water. He used more scientific words to describe it.

Second, he had me make sure there were very little to no rippling on the surface. I had worked under the impression that a small ripple was good, yet he asked me to make sure there was essentially none. So I pointed my circulation pumps downward, and to ease my mind of gas exchange I started running an airstone a couple hours over night. I had zero movement at the surface.

Last, since I was running two Eheims at the time, I moved the outlets to the middle of the tank, pointed them towards each other so when the water comes out, one outlet containing the co2 the other without, the flow mixes together and provided a more evenly distribution of co2 across the 6' tank.

So those three things solved the issue, after that it was just dialing the appropriate amount of gas into the tank, co2 concentration is balanced, pearling across the tank the last few hours of the night, growth has been great, and once I got it dialed in my algae issues were greatly reduced. All from a single inline diffuser on just one of the filters.

With the power of an FX6 I would imagine you could have the co2 enter from one corner of the tank and it would get pulled across to balance. Worth a try taking the spray bar off and let it flow out of the nozzle with less obstruction.
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