I've got my lights and CO2 on separate timers and am wondering what the concensus is for when the CO2 should come on prior to the lights and when the CO2 should be turned off? Say, for instance the lights come on at noon and go off at 10pm. Should the CO2 get a one hour's head start (turned on at 11am) and be turned off, say, 1/2 hour earlier (9:30pm)?

Thanks, Peter

I have mine set to come on 1/2 hour before the lights come on and go off 1/2 hr after lights out.

mine comes on a 1/2 hour before the lights, and goes off at the same time.

Mine is set to an hour before light on, I think I think the important thing is to check your CO2 levels when the lights first come in. If it is at 30ppm then you should be fine. If it is lower, you may want to try starting the CO2 a bit earlier.

because i have so many digital timers in service, ''$25.00 a pop'' i set my reactors to come on with lights and go off at same time.i think too much tech. is getting involved here.ambiant light also is different at different times where the tank is located.this light information,pro's and con's have worn out it's welcome.too many variables! the same go's for TEST KITS. regards,cornhusker

I've never had any issues with using the light timer for CO2.

some suggest you get better growth if the CO2 is high when the lights come on, but I think the fish and the time of day when the O2 is lowest balance that issue out.

Either way, I do not think you will find it that much difference, I'd be very surprised if you did. I tried aeration at night/all sorts of timer set ups, even adding pure O2 gas.


Regards,
Tom Barr

Helpful advise. Thanks everyone.