A new lesson -to- learn?

[Lyrek]

So, I thought I had a pretty good handle on my aquarium. I take care of my fish. I fieed them a variety of foods. I keep the water clean, the heaters and filters running. However, now I am starting to think there is something I am missing.
This evening (10pm) I came home to find one of my fish (some form of platy if I think it was) at the bottom of the tank. His tail fin is gone. His eyes are gone, his body cavity is wide open. He about a dead as a fish can get.
I don't have a shark in my aquarium! So what on earth could have possibly happened to this fish!? I am really tired of losing fish with absolutely no explanation!

He was alive, healthy and eating last night. I come home this evening and he is not only dead, but horrifically torn apart!

Can someone me let know what could be going on?

Tanks mates:
4 Gouramis: Dwarf, pearl, gold,
1 Sailfin molly
3 angelfish 1.5" to 25" (+1 in hospital tank- nearly recovered)
4 Serpae Tetra
4 Scissor Tail Tetra
1 RedWag Swordtail

20 Gallon Tall tank.

Thanks,
Adam

 

[skjl47]

Hello; Quite often when a fish dies the other fish pick it's carcass apart as you have described. If you have snails they will fed on the carcass as well. This is a common thing and has happened many times in my tanks over the years.

As to why the fish died, that is another matter. Sometimes I have never found out for sure. One thing that stood out to me is the list of fish in a 20 gallon tank. Some will get fairly large, such as the angels and the pearl gourami, for that sized tank. The angels will outgrow that tank if they live. Even if they are all small now, that is a considerable load in a fairly small volume of water. Such a number of fish can be kept in a 20 gallon tank by an experenced fish keeper for a time. A problem likely will be that any number of things can throw the water quality out very quickly. A bit of overfeeding that would be ok in a larger tank with those fish can turn into an issue very quickly. A single dead fish can add to the issues quickly in the tank and lead to other problems.

In other posts I have likened it to the difference between walking a nice wide path and walking a tightrope. My take is that you are on a tightrope with your tank. The fish you list in a much larger tank would become more like a caln stroll down a wide path. It may well prove to be that if you reduced the stocking density of the tank many of the issues could go away or at least be lessened. The stocking level of your tank may also explain some of the fish deaths you mention. I went to a very light stocking density some years ago and have had much better results with my tanks. Water quality stays good for longer intervials. The fish have fewer health issues and so on.

Another issue that has proven very common among the new fishkeepers I have know over some fifty four years is the tendency to overfeed. Almost all I have known have tended to feed too much and too often early on. I did so myself for a considerable time. You may not be among those who overfeed, but it is something to consider.

Good luck with you tank.