Hello, I've recently moved to Menlo Park, California. I tested the water here and found it to be extremely soft, that is to say, GH and KH tests show no hardness at all. I have a 20 gallon tank and have never been in an area with soft water before. I'd like to continue to keep livebearers as I enjoy them and have experience with them, but I know that they prefer a GH of at least 10. A LFS recommended a product which buffers the water and keeps it at about pH 7. It's Seachem neutral regulator. After using the product as per the directions, I test a GH of nothing, and a KH of about 7, a pH of about 8. Note I have no fish in this tank yet. Should I start over with some calcium carbonate? If so, what's a good source with reliable dosing (coral seems like a lot of guess work to me).