Testing after water change?

[Timandkatereef]

Hey I was wondering do you test for the Alk,Mag, Calcium after completing a water change? If so/not, why?

How long do you wait to test/dose after a water change?

 

[Randy Holmes-Farley Verified Community Expert]

It does not matter as long as you understand if the water change might be large enough to raise or lower what you are measuring. :)

 

[KrisReef]

If the tank is stable then I make sure to match alkalinity of the new water to the existing tank levels.

If I am trying to raise tank levels then I will add new water with elevated parameters to bump the tank levels in the right direction.

I measure soon after any bump to determine where the tank landed and then retest (tomorrow, or next week, or next month depending on how stable the tank is performing and how often I am testing. I don’t have an apex running, so I test accordingly. A stable system shouldn’t be drifting significantly once it is established.