[bolsy]

Can anyone tell me roughly how long co2 will stay dissolved in my tank water. I have moderate water movement in my tank. Will the co2 that doesn't get used today by my plants still be in the water tomorrow when my system switches back on. Or is it like if you leave a glass of coke for an hour it's flat. I have some surface aggitation but not much.

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[Wasserpest]

The best/easiest way to tell would be to use some sort of monitoring device. Obviously, that could be a pH meter/monitor, or you could buy or rig up a "drop checker" which will display CO2 levels via color changes of the pH indicator liquid. Search for "drop checker" and you will get a lot of ideas there.

 

[Darkblade48]

More likely than not, after a few hours, whatever CO2 is in your aquarium will likely off gas.

I notice that in an aquarium with moderate surface agitation, after the CO2 is shut off for about 4-5 hours, my drop checker is back to blue. Since the drop checker already has a delayed reaction time, this means that the CO2 concentration has been lower for quite some time...

 

[bolsy]

Thanks for the replies. I do have a drop checker which changes very little. Maybe need to change solution bottle. Was toying with the idea of getting co2 into the tank before the lights come on. If i start too early getting the gas into my tank it may be lost to the air before the plants can get to it. so i might leave it at an hour before lights come on.
Cheers Bolsy.

 

[Darkblade48]

Thanks for the replies. I do have a drop checker which changes very little. Maybe need to change solution bottle. Was toying with the idea of getting co2 into the tank before the lights come on. If i start too early getting the gas into my tank it may be lost to the air before the plants can get to it. so i might leave it at an hour before lights come on.
Cheers Bolsy.

An hour before the lights come on will probably be fine.

I have my CO2 turn on 45 minutes before the lights turn on, and then turn off 45 minutes before the lights turn off.