Alkalinity is slowly raising after a water change

[reefnerd68]

Alk has been a struggle for me lately. My alk after a 10% wc sits high at 12dkh then raises .5dkh per day. I’m stumped. I’m not dosing anything and the tank is light to moderate lps stocking.

 

[Randy Holmes-Farley Verified Community Expert]

Alk can rise from nitrate falling or being dosed, or from very slow dissolution of rock and sand, but 0.5 dKH per day seems excessive.

What do you use for evaporation replacement?

Maybe just monitor it longer and see if it wasn’t test error.

 

[Randy Holmes-Farley Verified Community Expert]

There are ways to lower alk, but I’d want to be sure it is an ongoing issue before doing it.

Lower alk in the water change water will help.

 

[reefnerd68]

Alk can rise from nitrate falling or being dosed, or from very slow dissolution of rock and sand, but 0.5 dKH per day seems excessive.

What do you use for evaporation replacement?

Maybe just monitor it longer and see if it wasn’t test error.

I’m using rodi for top off and not dosing.