The hardest part of setting up an aquarium is keeping yourself from rushing out and buying the most amazing fish ever.brandonhovis;4774422; said:
A marine tank will exhibit symptoms of 'new tank syndrome' for the first six months. During this time, you should stick to exceptionally hardy fish (especially for first fish). You will also need this time to learn about marine water chemistry and gather the proper equipment.
Keep in mind that MFK is predominantly freshwater. There is a marine section toward the middle of the home page. If you post anywhere else, you'll need to specify that you have a saltwater tank. Otherwise everyone will give you advice for a freshwater system. And that can sometimes do more harm than good.
You are trying to make a marine eco-system function with freshwater equipment. Sure it can be done, but the more you learn about what is out there, the more you will wish you had just started with the right gear to begin with. There is a lot of talk about cycling a tank, but in reality, it is the filter that is cycled. If you change filters mid-game, basically you will be starting from scratch. The easy way to stay with what you have is to just add a hang on skimmer (they lack awesomeness but they will get you where you need to be). A sump based skimmer is what you should set your goal at, but that is also going to be somewhat costly.
You are also going to need a saltwater master test kit (and a reef master test kit if you want to keep sensitive fish). For the salinity, you will need a refractometer or at the very least, a hydrometer. For water changes, you will eventually need to get a reverse osmosis system.
Lastly, it was probably osmotic shock that killed your fish. A lot of the time, "acclimating" fish means floating the bag in the fish tank for a while. It's rare that someone will point out that the difference in water chemistries and salinity of the bag and aquarium need to be accounted for.
