Additives/trace elements in a fowlr tank

none at all. Change 5% of your water every two weeks

 

You bet. Purple coralline will take some time. Once you start getting it on the glass, scrape it off and the flakes will 'breed' but overall the salt (depending on brand) will provide enough Kh/ca to keep things growing well. Adding things like 'purple up' can add huge ammounts to your ca and cause PH swings killing off fish. Remember, your PH can be effected by the number of people in the room with the tank if paramaters are off.

 

trace elements are taken up by large amounts of SPS.

You just need a little calcium & alkalinity, as well as lights enough to grow it.

 

If you are using reef crystals than you have enough of everything to be just fine. Reef crystals is a little beefier than the standard salt. If you have any coraline algae at all or cqn get a piece with some on it the fastest way to spread it is to scrape that stuff. Turn all your pumps off. Scratch the crap out of it if its on a rock. And let the particles settle.