Funny way to die?

Question
Dear Chris,
One of the tanks that I have is a ten gallon that I had set up for about 2 years. I had a few fish, nothing special, zepra, neons, sucker. Anyway, My brother had a male bata that was losing it's colour so I put it in my tank so I could take better care of it. Well, needless to say that all the fish in the tank were dead in a week. Now the weird thing is that all the fish died and stayed at the bottom of the tank and there scales "peeled" off in the water. I have never seen this before. Now I have cleaned the tank and set it up for my girlfriend to have fish in and the same thing is happening. I've never tested pH or ammonia levels before because I don't know what they should be. Any ideas whould be greatly appreciated. I mainly want to know if this is a common way for fish to die? Sorry about the novel!!  Thank you for your time.
Brandon

Answer
Hi Brandon;

The symptoms described could easily be from fish waste toxins. If the tank already had several fish in it, the addition of just one more can cause toxins to rise to lethal levels. If you added the old betta tank water to his new home, it makes it even worse. Now after cleaning the tank and setting it up again you have the problem of "New Tank Syndrome". It also includes high levels of toxins. I will give you a link to my article on new tanks after this letter. It could be a disease causing the problems, but check the levels of toxins first. Here is what you need to measure;

Ammonia - Should be "zero" in an established healthy tank
Nitrite - Should also be "zero" in an established healthy tank
Unsafe levels of ammonia or nitrite needs an immediate water change of 25% and again every day until levels start going down on their own. Use a water conditioner and be sure the new water is the same temperature as the old water.

Nitrate - It's okay at 40 ppm or less.
Replace 25% of your tank water every week to keep nitrates low.

pH - the actual level is not critical but optimum is 6.5 to 8.0. Your tank will just like to be a certain pH and your fish will adjust to it. Stable pH is much more important that a certain pH measurement. Partial water changes weekly accomplishes that.

Here is the link to my article on new tank syndrome;

www.xanga.com/expert_fish_help

If you find that there are no toxins present, let me know. It is a disease that we need to diagnose in that case.

At Your Service;
Chris Robbins