I don's have an exact schedule with water changes. I do at least a 10-15 gallon WC once a month minimum. Sometimes more frequently. I would recommend doing more than this on your new tank BTW. Mine ha been pretty stable. I do not dose any chemicals besides calcium because sometimes the IO Reef Crystals is a hair lower than what I like to have. Other than that once in a while I put in a few drops of Brightwell Aquatics KoralColor in (encourages biochrome production) in. I cannot say if this product has actually helped in coloration of my corals, but I picked up a 500ml bottle from my LFS to try out so I use it everynow and again. Also I will add some aquavitro eight.four if the pH changes on me. This product also raises carbonate alkalinity. This product does do what it says. I only use it when my pH gets a little lower than normal. Besides those things, nothing. I do keep a bottle of Seachem Prime to kinda rinse my hands off with before sticking them in the tank for any reason because It seems I do tend to wash my hands a lot throughout the day and I don't want any chlorine getting into my tank.-I use RO water.