I'm planning a 90 gallon community tank with heavy fish load and moderate plants, freshwater. I live in Illinois on well water and it's 400ppm GH with KH of 200. I'd like to keep angels and tetras. The water from my water softener is 60 GH and 200 KH but I'd have to add some Ca (no big deal). I'm considering mixing the both of them to get around a 150ppm GH. RO is not an option. Any issue with this?