Hi all. I have a 200L planted co2 injected tank and have been in this hobby for around 3 months now. I keep finding random fish dead early morning. Water parameters are all good and I even dose with ferts. Kh and gh are alos good. It seems to point to the PH swings in the tank which could be shocking them and dying thats why I find them dead in the morning.. PH with co2 on is 6.6 and with it off is 7.3.. what would you guys do to try regulate the ph? Would putting co2 on for 1hr and off for the other repetitively do the trick? Normal co2 runs for 7hrs sonlike this it would be on for around 4 hrs.. opinions and suggestions on this? Any one else has same issue like me?