CO2 Question

[adeebm]

So I finally have my CO2 regulator and my 10lbs bottle all filled up. My pH is 8.4 and the KH is 14. So that means that if I want 15ppm CO2, I should aim for a pH of 7.4? And the CO2 only runs while the lights are on I assume. So will the pH rise back up in the night and cause swings?

--Adeeb

 

[Faile]

If you choose to turn of the CO2 at night there will be some swings in the pH, but they won't affect your fish. It's not the changes in pH that affect fish, but rather changes in KH which are usually accompanied by changes in pH.

 

[adeebm]

No, i'm pretty sure fish don't directly care about KH levels. Carbonate hardness is the measure of alkaline buffers in the water. These buffers maintain a stable pH and stop swings from occuring. KH changes don't really affect fish at all, it's changes in pH which are harmful.

Anyway, I just want to know if most people keep their CO2 systems on or off at night and whether it causes pH swings either way.

--Adeeb

 

[rkilling1]

No, i'm pretty sure fish don't directly care about KH levels. Carbonate hardness is the measure of alkaline buffers in the water. These buffers maintain a stable pH and stop swings from occuring. KH changes don't really affect fish at all, it's changes in pH which are harmful.

Anyway, I just want to know if most people keep their CO2 systems on or off at night and whether it causes pH swings either way.

--Adeeb

Most people over the years have said that pH changes based on changes in KH are harmful to fish depending upon the rate of change.

Changes in pH based directly on the addition of carbonic acid have not shown to be stressful.

My CO2 turns off with the lights and comes on 1/2 hours before the lights.

I have measured the CO2 with a drop checked that contains a calibrated KH solution and the amount of pH change (CO2 loss) was very minimal. My pH would only change maybe .2 to .4 pH units over night. This only takes into account my setup. ie How much surface agitation, type of filtration, etc..

I have had the same fish for over 3 years. I wouldn't say the change in pH from the CO2 has had any negitive effect on my fish.

 

[adeebm]

Yeah I suppose pH changes due to KH would be worse because the TDS change would cause osmotic stress. But that's nit to day that pH changes unrelated to KH wouldn't be harmful, otherwise a KH of 0 would be fine.

Thanks though, if your tank is okay, then I guess it should be ok. *fingers crossed* gotta wait for my glass diffuser first.

--Adeeb

 

[maxst2]

My CO2 question since im going to be getting a automated system for pure simplicity/laziness

How long will a 5lb bottle last me? And I'd assume that a 10lb would last double the time?

 

[adeebm]

I think 5lbs will last you 6+ months depending on your setup. And yeah 10lbs is double.

--Adeeb

 

[rkilling1]

My CO2 question since im going to be getting a automated system for pure simplicity/laziness

How long will a 5lb bottle last me? And I'd assume that a 10lb would last double the time?

There are many factors that will influence that question.

How much surface agitation, how high of a concentration of CO2, how many plants, how much light, etc...

My 10lb bottle that goes to a 75 gallon tank as well as a 28 gallon tank, lasts about a year. The 75 is high light and the 28 is medium light.

 

[ChizerBunoi]

Yes you would need to drop the PH to 7.4 to get 15ppm.

My 10lbs bottle lasts for 4 months at 30ppm on a 90 gallon with a ph controller that is on 24/7.

 

[mgamer20o0]

Most people over the years have said that pH changes based on changes in KH are harmful to fish depending upon the rate of change.

Changes in pH based directly on the addition of carbonic acid have not shown to be stressful.

My CO2 turns off with the lights and comes on 1/2 hours before the lights.

I have measured the CO2 with a drop checked that contains a calibrated KH solution and the amount of pH change (CO2 loss) was very minimal. My pH would only change maybe .2 to .4 pH units over night. This only takes into account my setup. ie How much surface agitation, type of filtration, etc..

I have had the same fish for over 3 years. I wouldn't say the change in pH from the CO2 has had any negitive effect on my fish.

100% agree.

i would really look into adding a drop checker to measure the co2.

 

[JustOneMore20]

Just wanted to add that my co2 is only on with the lights and off at night and I have never had any problems with it. I have had some of the same fish for a couple years now.

You'll love your pressurized system!