Tom and everyone here that help sift through a lot of misinformation in this hobby, I want to thank you. What I think I know, KH stability is more important then pH stability (probably wrongish) while GH effects the osmoregulatory system. Should GH levels stay stable or is it more about just having enough? For example, the fish that we bring home - is the GH effecting how fish acclimate to their new surroundings? I would think matching temperature and KH are more important. Direct me to a more practical application or validate how these relationships (KH, pH and GH) effect caring for a planted tank full of fish. I just need some basic guidelines and direction. Maybe one or two fictional relationships that are still passed around. One more thing, I see on forums something about solubility of CO2 at low KH. My tack has been 30ppm is 30ppm and those who worry about CO2 solubility in water with low KH/pH read too much into the CO2/pH charts. Is there something to this misinterpretation? Does pH lower the amount of CO2 that is soluble in water, the way temperature does?