I believe there is a system called a deionized water filtration system that hooks up to your faulcet and knocks out all unwanted things in the tank water, PH comes out at 5.8, this system is mostly for discus, but the water is so damn pure that you will need to add the electrolytes amd PH to get the water to your demands. I've never heard of crushed coral either, but if it works, then it works. But I prefer my PH around 6.4-6.8, water temp at 86-88 when pbass are small. Feed bloodworms, mosquitoe larvae feeder guppies while babies, and some type of water movement for the surface to get the frozen foods to look like their alive from all of the water movement. Deisel is the man so listen to his advice especially.