well, when i first had a 45 gallon tank i had a oscar and jack dempsy, both loved feeder fish, i went to a lfs asked for 25 gold fish for three dollars, the guy goes gets them, and i look he gave me fifty instead, so i took it as a bargin and headed home. i was thinking what to do with all these fish, i didn't want to waste them, and i had no where else to keep them alive. so i did the most dumb thing ever, put them all in!, all you could see is two monsters going to town and flashes of gold being torn apart, i thought,i guess this isn't to bad. well two days go by and they ate all of them. my fish where super fat and not moving to much, i thought they were full. so i was running later that day back to the lfs and decided to take in my water for sampling, you guessed it, was completely toxic, i ended up doing a 50 percent water change and it was to late the dempsy did't make it. but the damn oscar pulled right through and still lives today, i lke to call it the unkillable fish after living through that.leasons learned