CO2, green drop checker only if CO2 on overnight
I've been playing around with my CO2 since staying it a few months ago. What's very confusing to me now is that my drop checker is green only if I leave the CO2 on overnight. I'm not able to come up with a reasonable explanation for this so I'm reaching out for help.
This is a 40B, medium planted, in tank diffuser, with a power head for circulation. I'm at 1bps and I do EI dosing. Lighting needs to be improved but it currently is a finnex planted+ 24/7. I'm still battling a little bit of hair algae but it's getting progressively better (assumption is due to increasing plant density).
I'd like to be able to turn off co2 at night if possible. Thanks!