# CO2 on a Timer



## inkslinger (Aug 13, 2008)

I see a lot of people put there CO2 in time with there lights , I tried this an saw my PH drop from 6.8 to down to 5.8 and still dropping by the end of my light cycle! on til i put it back on my Controller. Would a drop of PH kill fish like that my KH was at 4.5 and 3 bps for a 110g tank with 80lb of Substrate and my lights were on for 8hr


----------



## djrichie (May 15, 2008)

How densly planted is the tank.... From what you posted it seems like to much CO2.... If you have a controller I would just use that and keep my Ph at 6.5... the controller is the next step up from a timer on a CO2 system. Most people don't have them because they cost to much money...


----------



## Dmaaaaax (Nov 20, 2008)

I currently have my CO2 on a timer. What you typically see when you first start is your pH drop when you first add CO2. Mine dropped from pH 7 to 6.4 and my CO2 went from 2ppm up to 12ppm with a kH of 5. Then at night your CO2 is off so the levels drop and the pH climbs. When I first check the pH in the morning it was back up to 7 and the CO2 was down at around 3ppm. 

This is typical and does not hurt most fish, however, I found that I could fine tune the CO2 and add a few more on/offs at night so that I did not have to inject as much during the day. I now have my CO2 at 1 bubble every 2-3 sec, which gives me ~12ppm and pH 6.6. At night it turns back on 2 times for 1hr. In the morning when I take my first reading the CO2 and pH are still the same!

However all this is not necessary if you have a controller, you lucky dog!


----------



## inkslinger (Aug 13, 2008)

Left mine on the timer 1hr before and 1hr after the lights go out, my controller is set at 6.5


----------

