Questions on Marine Chemistry.

oh dear thats exactly what i'm talking about.

[dnsfpl]

if you are using a ph pen, get a calibration liquid

if confirm ph low, measure your kh
ideal ph is 8.1-8.3, kh 8-9

if both are lower than ideal, mix 1 teaspoon of NaHCO3 with water and pour slowly into sump
measure again the next day and repeat if necessary

if your kh is ideal, get some coral chips

cheers

Here is some good info i found on reef chemistry