I really have no idea what the exact parameters are in my tank. Some people say Rockhapton has hard water, while others say soft. I know the local pet shop that buys my guppies sells them as soft water guppies, because if you put my guppies in water that has had live bearer salts added, my guppies kick the bucket. Most of my tanks do have lava rock in them (which gradually breaks down), but the native tank doesnt have any. substrate wise I think its all inert with washed river gravel, some black sand and normal washed river sand. So nothing really fancy in the substrate. I also know I dont tend to get calcification from hard water on my tanks.