I have a 215 gal . I started today with a half a teaspoon. I have a bunch of different zoos in the tank and some lps. There always seems to be at least 1 or two fussing or just melt on me here and there. I have used hydrogen peroxide dips (hit or miss) in the past with some sucess. All my perameters seem to be ok except my nitrates which have crept up to 20 maybe higher(api test).I use filter socks a skimmer , gfo , rox.08, and small 5-10 gallon water changes once a week or so.I am hoping(not holding my breath) the zoos I have right now that are fussing get better and or my nitrates go down. Either would be pretty nice.I started with a half a teaspoon of the iherb stuff(thanks for the link and coupon)not sure if its enough or too much but I will keep you all posted