Oxygen and CO2 question

[Zombill]

Hi. Currently during the day I don't have my air pump on, so the CO2 won't off gas, but at night, when the lights are off, I turn it on. I'm going to be making a DIY co2 system and I was thinking at night the CO2 will be off gassed. So the question. Can I put the line for the air AND the line for the CO2 in the input of my canister filter? The gasses should mix in the filter and that way there is plenty of both all the time...right???

 

[rich311k]

I would imagine you could never rum the airpump and still get plenty of O2. The air pump is not adding O2 it is just creating surface movement which allows for greater gas exchange. You are not going to get dangerous levels of CO2 with a DIY setup. Unless you are greatly over stocked you do not need the air pump ever.

 

[Zombill]

Thanks!

 

[Zombill]

I did forget to mention that my tank(30 gal) is heavily planted if that matters

 

[mfdrookie516]

an air stone could potentially add co2 to your tank if it's heavily planted and you dont have great surface agitation

 

[Fishguy2727]

You want CO2 off gassing at night since plants are releasing it, not using it. If you add CO2 at night (without offgassing it) the pH can crash and kill everything.

 

[rich311k]

No way that happens with DIY, Plants give off little CO2 they do not respirate at nearly the rate animals do. I have had pressurized on all night with KHs under 2 no crashes, no deaths. PH crash is not what hurts the fish,. pH changes do to CO2 are meaningless, it is only if dissolved solids change that there is a problem due to PH.

CO2 kills by getting to a rate higher than what is in the fishes blood stream.at that point the fish cant release the CO2 and the poor little guys suffocate.

 

[Fishguy2727]

That may be what happened to you (or rather hasn't happened yet), but it has happened. People have lost entire tanks because their CO2 ran all night.

Do not run CO2 at night without an air stone running to drive it off, your fish are worth risking it.

 

[rich311k]

I have it locked in and the levels stay at 30ppm. Does not matter if it is day or night. Done properly there is no danger. As for DIY, you work that hard to make CO2 to drive it off at night. There is no way you will get deadly levels of CO2 in a 30 gallon tank with a normal DIY set up. Just not going to happen.

 

[mfdrookie516]

I suppose it could if you were using a 55g drum rather than a 2 litre or gallon jug. I could see if happening in a small tank, 10g or so, if it is set up very efficient. I've seen people say that they lost fish from their DIY co2 setup, but I dont buy it.

 

[NYREPS]

Hi guys here is my input on co2 I had just gotten a co2 system in a auction and I had been using it for the passed 3 months and I also have a DIY co2 yeast bottle and I notice when I wake up in the morning my drop checker would turn back to blue a very high ph and when the day comes when the co2 would drop back to light green and on my new 55 gallon and I got 40 neon and almost half of them had die do to high ph swing ,but I just found out that by turning my spraybar down my ph stay green all night , I had the spray bar pointed up in all my tanks for a long time and could not why it turns to blue in the morning but now I know so if you have a spraybar point it down and no co2 will escape in the middle of the night,let me know if I'm wrong

 

[NYREPS]

Oh and plus when I had the spraybar pointed up in the morning I would had to turn my co2 system to 2 to 3 bubble per sec and it would take about 6 hours to turn back to green ,but after finding out to point the spraybar down I wake up and my drop checker is green and all I use now is about half a bubble per sec and it stay green 24/7 and I use a lot less co2