Your kh, gh, and tds are high. Also, do you really need co2?
Little confused here. I thought high KH controls acid and thus PH swings. Therefore, my PH shouldn't be moving very much at all since I have a high KH. E.g. CO2 injection should have little impact on my PH. I'll test while it's off as well to see. I know that my drop checker doesn't move day or night.About the only thing I see is your Ph. How are your swings at night? I assume its on a solenoid and shuts off at night? With your TDS/GH/KH I imagine it is buffering back at night and might be causing a crazy swing in Ph. Have you tested maybe in the morning before CO2 starts again, it might confirm/discount what I think might be going on. Our neos never enjoy low ph water, but your numbers should still keep them alive and doing alright.
Co2 changes your ph all the time. That's why some use ph controllers with co2 to stop the swings. Drop checker is just for a quick check and is by no means accurate. Many guides here on how to dial in your com and take accurate readingsLittle confused here. I thought high KH controls acid and thus PH swings. Therefore, my PH shouldn't be moving very much at all since I have a high KH. E.g. CO2 injection should have little impact on my PH. I'll test while it's off as well to see. I know that my drop checker doesn't move day or night.
Yes, once a week. That spot by the heater is harder to get to and thus looks worse than the rest of the tank.That substrate is layered in debris, do you ever vacuum?