Testing Water

[Fishturd]

Is their a better time of day to test water from your tank versus when the light are on or been off. I know PH drops a little when the lights are off but what about other water parameters like Cal, Alk, or Mag, do the also drop when the light are off in the main tank. I also keep a light on in my fuge if that even matters?

[Loverotties]

I think Ph is only infected with light!