I am trying to set up an aquarium that I can keep as natural as possible so as few chemicals or additives as possible and need some advice. The aquarium is 125 gallons, and for equipment I currently have a Fluval FX4, Aqua Clear 70, and a Tetra UV sterilizer 36 watts. My tap water is ph 7.6, high test ph 8.8, Ammonia 0ppm, Nitrite 0ppm, Nitrate 0ppm, Phosphate 1.0 ppm, KH 3 ˚, GH 2˚. After setting and being agitated by an air stone for 24 hours the ph 7.6, high test ph 7.4, Ammonia 0.50ppm, Nitrite 0ppm, Nitrate 0ppm, Phosphate 0.50 ppm, KH 2 ˚, GH 2˚. I am thinking of stocking the tank with African cichlids, using Pure Water Pebbles African Cichlids substrate to bring up the GH. Any advice would be appreciated.