If your snail shells are suffering, you actually want to increase water hardness although there is a strong correlation between high pH and Hardness. Raising pH alone (especially chemically) will not help your snail shells. Addition of coral rubble or coral sand is the easiest way since it will buffer your water to a "natural" state which is high in hardness and pH and will reduce fluctuations. ie as acidity drops, more calcium carbonate will leech out to restore the natural balence. So it doesnt matter if you have too much. I use small dead brain corals which I can find along the beach. If you can only find coral sand and you dont want to mix it with your natural gravel and your filter is too full, you can put it in a stocking or nylon bag and bury it. Suggest you try about 500gm initially and see how fast this dissolves.... should take months.
When you say "inverts" do you mean this is a salt water tank?
When you say "inverts" do you mean this is a salt water tank?
