I built myself an auto-topoff unit and I was wondering what additives I can put in the 5 gallon container so i would automatically get all the additives I need in my reef tank through my auto top-off. I have heard that I don't want to use a powder kind of calcium additive because it will sink down to the bottom and get sucked through my hose and mess things up. Right now i have Aragamilk and some iodine. I want to be able to add everything in the container and have an all-in-one mixture if you know what I mean. Pplease let me know what to use for a calcium additive and any other additives I might want to add for my reef tank. I also have a balance block in my tank right now which seems to work well.
Another thing is when I add the additves in my top-off water, do I add enough just for the 5 gallons, or enough for my whole system. I guess what I am asking is how much should I add to my top-off water to be able to forget about additives and let it go automatically for a week or so?