as Grif said, Lynn did an excellent job covering things, but if i might add, a lot of freshwater shrimp keepers and discus keepers use ro water exclusively. to combat that we remineralize with products which are shrimp safe.(frogs are a piece of cake considered to how sensitive some shrimp are) Fluval makes a wonderful shrimp mineral supplement. the only catch being is there is no precise formula for using it (i.e. 2 drops/gallon sort of thing) we normally test all parameters while mixing the ro and tap to get parameters where we want them. i'm not saying this is the way to go, but it is another option for you to research.