How much CO2

[DaWolfe]

Ok, so I now know how to use a T valve on my regulator....

Now the question is how much CO2?  I have read pretty much all the posts on this and here's what I am doing and please comment.

90 gal
PH: between 6.0 and 6.5
Lights: 4x54W T5HO (2x12000k and 2x6500k) =  216W total on for 10 hours
I do not have a solenoid valve yet looking for one. I will manually shut off CO2 at night at the same time has the ligths (10:00) and start it before I leave in the morning (6:30) but lights turn on at 12:00  IS THIS A PROBLEM? CO2 on 6 hours no lights???
bubble count:2 bps

Livestock: 5 ottos

I have set some water aside and will test PH in 24hrs and see if it dropped, like other post said I will try to aim for a decrease 1 PH.

Am I on the right track?

Thanks for your help.

[exv152]

If you run CO2 with the lights off you run the risk of asphyxiating your fish, especially if it's for 6 hours.

[pm]

If you run CO2 with the lights off you run the risk of asphyxiating your fish, especially if it's for 6 hours.

True, but this risk can be eliminated by using an air stone and pump on a timer during the non-light periods.  The surface agitation will gas off the co2. 

[exv152]

Best thing is to do it right, get a solenoid and connect it to a timer. No need for bandaid solutions if you set it up correctly from the start.

[charlie]

IS THIS A PROBLEM? CO2 on 6 hours no lights???
[

That will all depends on the plant mass, fish load , type of diffusion & how effective it is, that said do it on a day you are home to monitor it or as mentioned put an air pump & stone on a timer so the pump kicks off 3 hrs( example) before the lights come on.
Errol