stop dosing the cal and buffer. there is a chemical relationship between c al,alk and ph. its a bit complicated, so do a search on them and you'll see what i mean. people dose calcium and alk because their corals are consuming them on a regular basis. if you keep adding them and nothing is getting rid of it you will run into a number of problems with you ph and you may even start to see the calcium start to precipitate. it will look like it is snowing in the tank.