water changes

shouldnt u do em once a week?

o wrong forum by the way

Depending on the bioload, changing 25-50% of the water is recommended - you'll have to do at least one water change per week.
The more pristine the water, the healthier they are, the more comfortable they are, the brighter colors they have and faster they will grow.

Fin rot and cloudy eyes could point towards bad water quality, in particular high ammonia levels. High ammonia can be caused by an uncycled tank, rotting food left-overs, or a filtration system that is inadequate.
Did you get the all the fish at the same time? If you received your Supers and Piraya later, that may be the cause of death. Where the Cariba have already adapted to the water (which is not necessarily a good sign - even fish that seem to do well can get damaged under bad conditions), it may have prooved too much for the other fish.

*Moved to Water Chemistry*

Fin rot and the cloudy eyes could also have pointed to a severe drop in ph from all the decaying organic matter in the tank as well. You really need to do a much much better job on your water changes, it's the single most important factor in keeping any fish happy in the aquarium

Swimming upward on an angle is a sign of gill duress. Possible nitrite poisoning was cause of death. Sounds like tank wasn't cycled. If it was cycled you need test kits to make sure your water change schedule is sufficient. Next to cycling tank water maintenance is most important.

Thanks guys, i think i know what the problem was. I had a couple of plants that got uprooted and they were floating on the top of the water a few days. When i went to take it out last night i found a piece of shrimp and a part of one of my reds which was killed by my caribe, rotting away. Damn im an idiot i should have taken it out earlier. Anyway doing a 50% water change today, and a 25% weekly from now on. Thanks again for all the help.