Instead of worrying about how many bubbles per second (the rate we usually use to measure how fast we're adding CO2), instead concentrate more on the health of the plants and fish. If you're sending the fish to the top to get air, you need either less Co2, or more surface agitation. I don't use a pH regulator, as I'm not too concerned over pH swings, it won't harm the fish if the pH falls via Co2 injection. I just use one setting all day long while the lights are on, and have no problems.
Also, the ph/KH scale isn't a very accurate way to measure actual CO2 content of the water, too many variables can affect either measurement, a drop checker is somewhat more accurate. I don't use one of those either though...
Finally, the number of bubbles per second you see may not translate from one tank to another, based on the size of the bubbles, etc. Just let the fish and plants be your guide, and adjust slowly. Good luck!
Also, the ph/KH scale isn't a very accurate way to measure actual CO2 content of the water, too many variables can affect either measurement, a drop checker is somewhat more accurate. I don't use one of those either though...
Finally, the number of bubbles per second you see may not translate from one tank to another, based on the size of the bubbles, etc. Just let the fish and plants be your guide, and adjust slowly. Good luck!