PH Problem

[PrettyFishies]

Can't seem to keep my PH up.

125 gal, IO Reef Crystals, changes every two weeks, have a refugium with Crushed Coral (separated from sand on top).

I've used a liquid reef PH buffer by Seachem, but it's pricey and doesn't get me up to 8.4. I hover around 7.9 +/- .2

Any ideas?

 

[bighabeeb]

Kalk will definitely help get the PH up a bit, but use it cautiously.

How old is your system? PH can fluctuate pretty heavily on newer systems.

May also want to add (if you don't already have one) a powerhead up by the top of the tank rippling the surface: increases co2/o2 transport and that has the effect of helping keep PH where it should be.

 

[PrettyFishies]

System is going on 11 months.

I have two PH's at the top breaking the surface.

Never tried kalk. I do use an ATO unit, maybe I should be adding something there?