Additive question

[JazzMann2]

Okay, My Ro/DI unit is set to be delivered tomorrow.. Do I need to put any additives in the water? Probably not in the top off water, but what about for the water change makeup water?

Thanks in advance,
Jeff

[saltyseaman]

YOu don't need to add anything to the make-up water. There is stuff on the market that you can add, but you don't *need* to. Ideally, you don't need to add anything to the "Water change makeup water" either, except for salt of course. But, if you mix up some saltwater with your 'water change makeup water" and find that after testing that New Salt Water your levels aren't where they should be, then you may need to put some additives in to get those levels up to proper levels.

These should guide you through what those levels are.

http://www.reefkeeping.com/issues/2004-05/rhf/index.php

http://reefkeeping.com/issues/2005-11/rhf/index.php

[Horace]

Right..you dont NEED to add anything typically. But most salts are deficient in certain areas and that should be addressed before you add it to your tank. For example, Instant Ocean salt typically runs low on thier calcium, and low on thier Magnesium. Those two things are often increased before adding the WC water to the tank. I typically just boost the Mag because I can easily add Ca with no adverse reactions to the tank if need be. Magnesium is something you want to keep high (1300+) and IO is notoriously low (about 1200). You dont want to add 100ppm to your tank instantly because mag should be added slowly. So what you ideally want to do is keep your tank at 1300+ all the time and match the WC water to that before you add it. HTH!