Do you run CO2 all day or partially?

[greenaqua]

I just setup CO2 on my new tank. Do you usually run this all day or only when light is on? my tap water is 7.4, I just ran for few hrs today and now my tank is 6.8

If I keep it all day, will it have a stable PH and how low can of ph can it get?

If I keep only when light is on, how much swing in ph should I expect? and will this swing affect small tetras (Neon, Rummynose) and cherry shrimps?

[Wolf19]

From my readings on this website I personally won't be running mine all the time. Start 30 mins before lights go on, and turn off 15 mins before lights go off.

The plants will not be using CO2 when the lights are off. Not sure what type of pH swing you can expect, but if you run CO2 during the night I think you run the chance of gassing your fish because the plants are not using it for photosynthesis.

[freph]

I run it when the lights are on.

[Dx3Bash]

On 30 min before lights on. Off 30 min before lights off.

[Darkblade48]

Originally Posted by greenaqua

I just setup CO2 on my new tank. Do you usually run this all day or only when light is on? my tap water is 7.4, I just ran for few hrs today and now my tank is 6.8

Originally Posted by Dx3Bash

On 30 min before lights on. Off 30 min before lights off.

+1. I do this also.

Originally Posted by greenaqua

If I keep it all day, will it have a stable PH and how low can of ph can it get?

Injection of CO2 can only lower pH to a certain value (I forget the precise value at this time).

Originally Posted by greenaqua

If I keep only when light is on, how much swing in ph should I expect? and will this swing affect small tetras (Neon, Rummynose) and cherry shrimps?

In general, pH swings that are caused by CO2 will not be harmful to livestock.

Rather than watching your pH, I would recommend that you use a drop checker with a 4 dkH reference solution so that you can first ballpark the CO2 levels you have, and then monitor your livestock carefully from there to see if you can increase (or you may have to decrease) your CO2 levels.

[HD Blazingwolf]

I like the ph difference for a ballpark reference before a choose drop checker at this point. Between a. 8 and 1.0 ph drop is usually sufficient for most plant needs and light intensities, once u go the high light range, more may be necessary. But ph drops are how i tune my tank in the beginning then adjust from there.

[Xalyx]

Originally Posted by HD Blazingwolf

I like the ph difference for a ballpark reference before a choose drop checker at this point. Between a. 8 and 1.0 ph drop is usually sufficient for most plant needs and light intensities, once u go the high light range, more may be necessary. But ph drops are how i tune my tank in the beginning then adjust from there.

So do you mean you use the change in pH to tell you how much co2 is needed? I had my Co2 controlled by a Milwaukee pH Controller and I didn't like the results, does a method like that result in less Co2 or is it entirely plant dependent?

[HD Blazingwolf]

Originally Posted by Xalyx

So do you mean you use the change in pH to tell you how much co2 is needed? I had my Co2 controlled by a Milwaukee pH Controller and I didn't like the results, does a method like that result in less Co2 or is it entirely plant dependent?

CO2 drops PH..

so i start my tanks with a 0.8 PH drop of co2 injection and adjust the co2 level from there
generally my tank take a 1.2-1.4 ph drop to have sufficient co2 levels.
I have lots of light

co2 levels are really determined by the plants, if they are growin properly for their light level. then you are sufficient. if leaves are curly, discolored, stunted in size, etc but you know you have enough nutrients, then this is co2

[greenaqua]

Read there are PH controlled CO2 injectors? Who is that targeted for? If fishes can accommodate PH swing caused by CO2 can I ignore those controllers? I am afraid to pump too much.. I am just using 1 bubble per 2 sec. So far they are doing ok.. been two days of using this...

[Darkblade48]

Originally Posted by greenaqua

Read there are PH controlled CO2 injectors? Who is that targeted for? If fishes can accommodate PH swing caused by CO2 can I ignore those controllers? I am afraid to pump too much.. I am just using 1 bubble per 2 sec. So far they are doing ok.. been two days of using this...

While fish can tolerate the pH swings caused by CO2, they cannot tolerate high concentrations of CO2.

Having a pH controller control a solenoid that turns on/off CO2 will allow you to control CO2 concentration via an indirect measurement (pH).

So for example, if you slowly increase your CO2 injection rate until you see your fish gasping for air, and find that your pH is (say) 6.4, then that would allow you to set your pH controller to a tad higher (say,) 6.5 or 6.6 without fear that CO2 concentrations would rise too high and suffocate your livestock.