Ok Ms Jenny.. I too have the reef buddy... The reef buddy only filters out chlorine. Chloramine is in many public water systems. Yours probably uses chloramines too. (You can contact them for verification) The aquatic life website says that it doesn't filter chloramines btw. I bought an additional canister and an additional carbon block from aquatic life from Amazon... The 10 in kind.
Or, for now, you can purchase:
Chloramines last much longer in the tank than chlorine. If you purchase the api product, treat all water being added to the tank.
So there is your first issue.. chloramines.
How often and how many gallons do you change out with your Kent Salt?