I have had a reef tank for 3 years now doing OK with water changes and a big skimmer. I am getting some very high end pieces now and I don't want to make a mistake. I just bought a Walt Disney frag and a Sexy corals Dynamite chalice along with many others from various venders. I have been using kalk by putting a few spoonfuls into a 5 gallon bucket and pouring RO water into it and putting the lid on it till the white settles at the bottom then pouring into the sump as the water evaporates. I have been using the kalk over and over replacing it about once a month or just putting more in and leaving the old. many times can you actually use the kalk before you need to throw it away and use new stuff. This is a pretty newbie question I know but I have never had a reason to worry about it but now a accident or incident could cost me a LOT of money. Where can I go for a crash course in reef chemical for the ADD idiot.