ca/mg dosing question
I don't know if there is a thread similar to this but I couldn't find one. I have very soft water around 0-1 KH and 0-1 GH. I want to dose CaCl2 and MgSO4 to increase my GH to around 4-5 dGH. I was wondering when the best time to dose would be. Should I just dose after each weekly 50% water change or should I dose on an EI schedule? Will the water hardness decrease over time from the plants using the nutrients?
If I dose after each water change should I just add enough to raise the new water to 4dgh, or enough for the whole tank?
I have a 29g tank, so I was thinking of adding 3/4 tsp of each to the 15g water change. Does this sound right?