Poll: Do you run your CO2 24/7?

[elwaine]

The pH in my tank varies from 7.6 (before lights and CO2 turn on) to 7.0 (after an hour or so of CO2). The RCS and fish seem happy and quite healthy - although it's been only a few days that they've had to endure the daily pH flux. Anyway, I was wondering how many of you run CO2 24/7 vs. how many run CO2 only with lights on.

Thanks for participating!

 

[An t-iasg]

I control my CO2 with a pH meter (the solenoid turns on and off according to the pH value). Sometimes I hear the solenoid click on or off at night when the tank lights are already off and the room is dark. My fish have a pH variation of 6.7 to 7.1 all the time. pH fluctuations due to CO2 don't hurt the fish.

 

[elwaine]

I control my CO2 with a pH meter (the solenoid turns on and off according to the pH value). Sometimes I hear the solenoid click on or off at night when the tank lights are already off and the room is dark. My fish have a pH variation of 6.7 to 7.1 all the time.

Two questions for you:
1. If the CO2 is controlled by a pH metering device, what accounts for the pH variations of 6.7 - 7.2?
2. Since plants do not use CO2 without light - and in fact use O2 and produce CO2 in the dark - why run the CO2 without the lights?

pH fluctuations due to CO2 don't hurt the fish.

That is my initial thought as well... although it might depend on the variety of fish one keeps. For example, I've read that Discus do not like pH variations.

 

[neilanh]

Running CO2 at night is just a waste of CO2, however if you don't have a solenoid to control this, it doesn't hurt anything in the tank either.

Those with a soloenoid and a timer prefer to kick the CO2 in about an hour or 2 before lights on to allow the water to saturate before the plants kick into the photo period.

 

[shrek_vn2002]

Running CO2 at night is just a waste of CO2, however if you don't have a solenoid to control this, it doesn't hurt anything in the tank either.

Those with a soloenoid and a timer prefer to kick the CO2 in about an hour or 2 before lights on to allow the water to saturate before the plants kick into the photo period.

I use the same timer for light and co2. Do i need another timer for co2 to tuen it on an hour before the light on?

 

[elwaine]

I use the same timer for light and co2. Do i need another timer for co2 to tuen it on an hour before the light on?

Yes. If you want to start the CO2 earlier, you'll need another timer.

The operative word here is need. You don't have to start your CO2 before your lights turn on. Look at your plants. Are they growing nicely? Do they pearl? Is algae under control? If the answers are yes, you need not change a thing. In fact, one could argue that you shouldn't change what you are currently doing. Once you change one parameter in a balanced environment, you may have change others to re-set the balance. So if you start your CO2 earlier than you are dong at the moment, you might have to change the way you use ferts.

 

[mgamer20o0]

i run my co2 24/7.... there are reasons to do all 3. ph controller, 24/7, and off at night.

 

[An t-iasg]

Two questions for you:
1. If the CO2 is controlled by a pH metering device, what accounts for the pH variations of 6.7 - 7.2?
2. Since plants do not use CO2 without light - and in fact use O2 and produce CO2 in the dark - why run the CO2 without the lights?


That is my initial thought as well... although it might depend on the variety of fish one keeps. For example, I've read that Discus do not like pH variations.

Sorry, did not see this immediately

1) The pH meter is set at 6.8. It is not a digital setting, just a knob, so the setting may be at 6.8 or 6.9. The meter turns the solenoid on, allowing the CO2 to flow, when the pH rises to about 7.1 or 7.2. When I happen to be in the room when it clicks on, the digital reading says 7.1 or 7.2. The CO2 runs until the pH falls to slightly below the setting. When I'm in the room and happen to see when it clicks off, it's usually at 6.7. This cycle happens all day.

2) I prefer to keep a steady amount of CO2 in the tank, day and night. I don't want to run the CO2 constantly all day when short bursts will do. I have small tanks (10 gallons) and the CO2 burst on-and-off suits those tanks just fine. It's a matter of preference; running the CO2 constantly when the lights are on won't hurt anything. Using the pH meter to control the CO2, I have had a 5 lb. CO2 canister on my 10 gallon for a few months short of two years now. I feel that running the CO2 with the pH meter conserves the CO2 and that is important to me.

And yes, the statement that pH fluctuations caused by CO2 levels won't hurt the fish is a true statement most of the time, but there are always sensitive fish.

 

[shrek_vn2002]

Yes. If you want to start the CO2 earlier, you'll need another timer.

The operative word here is need. You don't have to start your CO2 before your lights turn on. Look at your plants. Are they growing nicely? Do they pearl? Is algae under control? If the answers are yes, you need not change a thing. In fact, one could argue that you shouldn't change what you are currently doing. Once you change one parameter in a balanced environment, you may have change others to re-set the balance. So if you start your CO2 earlier than you are dong at the moment, you might have to change the way you use ferts.

Thanks... My plants are doing fine. So I think I still keep it like this for now.