Should I do a water change? and what chemicals do I need

[cnl83]

My tank is about 6 weeks old. 55 Gallon, a good bit of live rock.

The LFS talked me into getting some Damsels. However I am concerned about a water change. So I bought a few damsels. My ammonia levels are between 0 - 0.25. 0.18 if I had to guess the color. Should I do a water change now? The fish have been in the tank for about 4 days and are doing really well. I have done any water changes yet. The only water that has gone into the tank is top off water. My protien skimmer is working very well I might add.

Also, are there any chemicals I should be putting into my tank? I have not found any articles related to chemicals for new tanks.

[leebca]

The advice you are following is not the best advice available. I would be concerned about taking such advice. One thing to do is get advice from others on the advice given. This seems to be what you're doing, so you want to make it a normal or usual thing.

This post tells you how to start a marine aquarium. It has in the post other links that answer the questions you're asking. This post and the ones it links to are very detailed and if I try to write something about their contents there is a very large change I will miss something. So I want you to do a lot of reading. Here's where to start:
Setting Up a FOWLR Aquarium

In short, the addition of fish in a tank with ammonia readings is poisoning the fish. Fish can't talk to us (obviously) and don't always show signs of stress, until they are about to die. So, you want to learn one important thing -- though the fish look fine, they are being poisoned which will shorten their lifespan in your care. I don't think (and hope) you want this.

Do water changes daily and do a large water change (over 80 percent) as long as you detect ammonia and/or nitrites. You need to get that poison away from the fish. In short, your aquarium really isn't ready for fish and the water changes is all you can do, other than returning the fish or finding them a proper aquarium.

Since the water changes will be large, you need to follow these guidelines: How to Make a Successful Water Change

Good luck!