Weird coloration in my Molly

Question
I have recently set up a tank (it's been a little over a week now - so very recently...), and this is my first one. I've had numerous problems already and have gotten some answers, but would like more advice. I am also a little concerned about my molly...

Firstly, my fish keep dying. I talked to the local pet store and they tested my water. Evidently, it was high in ammonia. I have purchased some ammonia cleanser and water conditioner. Currently, I test the water for ammonia content once every other day and do a small water change (less than 10%) if it's high. I replace the water with fresh water, that I've cleaned with the products mentioned. So far, things seem to be going well since I've started this, but can you suggest anything else? When I was younger, I used distilled water for my betas. Can I use that now instead of having to purify the water every time?

Also, I have a lyre tail dalmatian molly who seems to be one tough cookie. He's outlived 2 silver mollies and a black molly that have all been, unfortunately, lost because of the ammonia. Now, however, he seems really languid. He spent most of last night chilling by the top of the water, and is currently sitting in a crater at the bottom of the tank. I'm worried about him possibly being ill, and just noticed a strange strip of orange-red discoloring at the top of his dorsal fin (sorry if my terminology is off.....) Is he ill? I've been feeding the fish a food that is supposed to bring out reds and oranges in tetras, but is supposed to be okay for other fish too. Might this have something to do with it?  I'm planning on getting new food soon, any way, since the stuff I have now makes the water pretty nasty. Also, planning to vacuum the gravel this weekend w/ my friends gravel vacuum. Is this worth it? Any suggestions?

Questions:
- set up 9 days
- 5 gallons
- 1 Lyre tail Dalmation Molly, 1 red crab, 1 long finned black skirt tetra.
- 2 fish, 1 crab
- Aqua-tech "ez change" #5 filter (walmart brand...I know, bad choice...first tank, and I'm a poor college student :(  )
- Don't know pH and nitrite. Ammonia ~.5 (just changed water) Planning to get more test strips once I quit being broke
- I end up changing the water every other day or so, but only enough to introduce new, clean water.
- less than one gallon.

Answer
Hi Courtney;

Your tank is simply in the break-in period. Ammonia is very normal at this stage. The problem you have though is that there are too many critters in there to get it through the break-in safely. This process is also often called "Cycling" and "New Tank Syndrome". It takes up to 8 weeks to complete and sometimes fish can get very sick during this time. Keep making frequent water changes but just use regular tap water and add a water conditioner. Distilled water is not safe for fish because it is missing important minerals that they need. It is sometimes used to correct water chemistry problems like high mineral content, but it is only mixed, using mostly tap water, never straight distilled-only in a tank. Anyway, keep making those water changes. BUT....Don't vacuum the gravel yet! The system is too new and is trying biologically balance. Beneficial bacteria that is trying to develop in the gravel should not be disturbed right now. Here is a link to my article about this whole crazy process to help you get through it;

http://www.xanga.com/Expert_Fish_Help

The food you have is just fine but feed only a very tiny bit once a day. The fish and crab must finish it from all areas of the tank in five minutes or less. Your molly needs veggies too. They need foods like squished peas, spirulina algae, tiny bits of romaine lettuce, cooked green beans, cucumber slices, cooked shredded carrots, etc. Feed a tiny bot of one or two of those every other day or so along with the flakes. Your other fish and your crab should like it too. It's good for all of them. The five-minute rule doesn't apply to veggies. They can be nibbled for several hours. They don't rot and pollute the water like flakes and pellets do after just a few minutes.

You may have to reconsider your choice of fish for this little tank too. Mollies get too big to stay happy and healthy in a five gallon. They need at least a 20 gallon because of their potential size of six inches and larger. Your Black Skirt Tetra needs the same size tank too. They are very active fish that grow to be 2 inches long. Both mollies and black skirts are also schooling fish. They need to be in groups of 3 or more to feel safe and happy. Your crab is fine but he needs a lower water level and a rock or something to get out on land once in awhile. Here are profile pages about all your guys to help you know more about them;

http://badmanstropicalfish.com/profiles/profile40.html

http://badmanstropicalfish.com/profiles/profile24.html

http://badmanstropicalfish.com/profiles/profile101.html

Your tank is better suited for smaller fish such as neon tetras,   danios, white clouds, cory cats, guppies, etc. Even just a male betta and a school of three cory cats would be better than what you have now. You just have to stock slowly with only one fish to start with. Read my page on new tanks at the link I gave you so you know why.

I hope everything works out okay...

At Your Service;
Chris Robbins