1. FOR A FISH: Ask your dealer what his Salinity is, and set your quarantine tank to that, precisely. The minute you open your bag, test the water to be sure he's right, and that you are, within .001 of a salinity-match; and a quick ph check is not a bad thing either---(if your ph should be bad (remember bag-water ph starts shifting the second the bag is opened) or if the salinity is not what you were told it was, a drip acclimation may be your only resort, especially if you have an especially fragile...

1. if you're going to have corals you need to aim at having either an all-in-one tank---or a sump, skimmer, and good lighting. Your rock and sand take the place of a filter.
a. stony coral and clams: need brighter light, good circulation. For sps (colored sticks) you need high flow and a super skimmer.
b. 'soft' coral is more forgiving, can exist without a skimmer if you don't push it, but it's a good idea to have one.

2. if you're fish-only you can get by with a filter:...

I'm going to start very slow, very basic, and work toward the lesser known things.

1. your salt mix is not just salt. It's dry seawater. And that means not only salt, it's calcium, magnesium, iodine, selenium, boron---read the label on your salt mix.

2. evaporation never evaporates the minerals. It only evaporates the water.

3. animals and plants suck up part of the minerals. So TWO actions unbalance your tank---evaporation increases the mineral concentration---and...