Worse I have ever seen is at one of the petstores around me. I usually never go there but.....
They had in one 55 gallon a 2.5 foot silver arrowana
which looked terrible. The other 55 had a bunch of large cats in them all from 9-12": 2xRTC 1x asian RTC 2xTSN 1xMarbled Pim. Then on top of that they had 3 maybe 8" oscars with BAD HITH. All that was on the tank was an undergravel with bubblers in it! I walked outta there and said I am going to TAKE that silver aro if it isnt gone next time I go there. It is rediculous.
Chad