I have been adding baking soday, 1 teaspoon per 50 gallons for the past week or so. It goes up initially but by the next day it continues to drop back down. Calcium and PH are fine and I am doing weekly water changes 10-15%. My KH starts off at 8 then goes up to 11 hours after dosing then back to 8 the next evening. Any thoughts? I have no fish and few mushrooms with a DSB and LR.