what's wrong with my fish?

[Lauren]

Hi, I'm new, and I've made a few mistakes so far that may be taking the life of one of my fancy guppies right now. He's been sick for a few days now, at first he was hanging out on the surface near the filter pump for 80% of the day, and then he moved to one of the caves where he was resting on the bottom. I thought he was dead this morning where I found him there, I went to remove the cave to retrieve him, and he slowly swam out. His colors are very faded and he'll swim around only when he feels threatened (I tried to bring him near the surface to get him some food). There are a few things that I think may be causing this.

First off, I made the mistake of mixing my guppies with danios. For the most part the danios chase each other around and don't care much about the guppies, but I look in form time to time to see a danio not only chasing, but greatly harassing a guppy. Both male fancy guppies have pieces missing from their tails. I need to return one or the other breed to the pet store, but I've been so busy for the past few days that I can't find time to drive 20 minutes to the pet store I got the fist at. I think the stress from the danios may be effecting my other fish.

Second thing that may be doing this is the water temperature. My room is a sauna in the summer time, and every day I have to switch out some of the water for very cold water to struggle to keep it in the right area. I've been turning the light off during the day, but so far that hasn't helped. I fight the temperature increase hard, but I'll walk by it in the late afternoon and see the temperature around 83, when I quickly cycle out some water for even the second time in a day. Could this be effecting the life of my fish? And is there a way to cool down the tank?

I can't think of much else. The water is treated for chlorine, but I don't have a test kit (again, need time). I'll be getting one asap, but the other fish, even the other guppies seem happy in the water. I have a filter, and the water is chanced frequently as well.

[PumaWard]

Hello,

First off, don't worry about it being 83, your fish should be able to handle that temperature. Second, never put cold water into your aquarium. The fish need to be able to adjust slowly to new temperatures and you may be shocking your fish by adding cold water.

Next, what are your water perameters besides the temp, i.e. pH, ammonia and nitrite levels? The way your guppy is acting sounds remotely like ammonia posioning.

How large is your shoal of danios, the reason they may be attacking your guppies is because they are in to small a shoal and feel threatened. You probably should have at least a shoal of 6 danios. Finally, how large is your tank and what is your regular mantenance cycle? The more information you give us the better we can answer.