i have a 75 gallon tank that i am setting up as a W/A biotope tank with kribs, congo tetras, butterfly fishj, brown knife, leoperd cntempoma and some upside down cats. my q is how importent is ph? from tap my ph is 8.4. how do you softing water? filter through peat moss dos peat in the filter work? if i alter it how much tap water should remain 1/4 of the tanks volume. just wondering if you guys and gals have any secrets