pleco death.. do i have ick or velvet?

Question
Hi,
when we first got our tank .. we werent sure how serious we'd be about it.. but i am now very serious to the point of obsessive.  I have a 55 gallon tank.  I keep the temp at 78.0. I started with a geophagus, a sarvus, 3 parrots, 2 rosy barbs, 4 sacrificial danios, 2 tiger barbs, 2 irainbow sharks (i know), 2 mollies, a crayfish and my favorite figure 8 puff daddy.  we had the tiger barbs, 2 danios, and the crayfish die. up until this point i was doing water changes monthly with vacuum cleaning.  i realize i was feeding too much.  Anyway, we decided to do nice lighting so i was determined to clean the tank up..  I took out 2 parrots, 2 danios and the poor, smaller, beat uup on rainbow.  I added 2 plecos, a jack dempsy and a peacock cichlid.. oh and 3 rainbows... and for some strange reason my husband put 4 tigers in.  I new i was over my head at this point.  i still had the same filtration system.  suddenly the fish started to hang out at the top gasping for air.  I took a water sample to the marine warehouse and the only thing out of wack was my phosphate.  He said the stock filter that came from walmart wasnt doing well.. so i got a new filter. He told me to do a weekly water change until i can get the gravel under control.. 25% to 50% so today was the 2nd.  When i got home i found my bristlenose dead in the corner-looked like someone had started eating him.. but not sure.  Now my 2nd pleco is holding onto the bottom of my driftwood not moving.  read about ick and velvet so i went and got very big flash light (tank light off) and looked around for the fish.. loking for snything.  when i turned the flashlight his way he barely blinked and it looks like he has gold glitter around his mouth, the edges of his fin.. please help.. i feel terrible that i killed a pleco already and am really worried that the 2nd pleco will be laying on the bottom of the tank in the am...i appreciate any help you can give me

thanks,
dawn

Answer
Hi Dawn:  wow... ok... your problems are complex... you basically have an aggressive tank that is stressing everyone out but the puffer... You have too many nipping fish that are causing wounds... small probably... that are getting infected by the tank water and high chem levels.  

Raise the temp to about 86 degrees, add aquarium salt per its instruction label.  You are going to need a strong med-antibiotic  Quinine comes to mind... This is just to help control the immediate problem... the real problem are the fish themselves... Its difficult to kill a pleco... But ... barbs, jack dempseys, and that puffer are all nippers... you are going to have to get rid of some of those fish... if you keep the puffer... keep just the puffer... do not add another puffer as they will kill each other... You need to go back to that store and read them the riot act for selling you all of these fish... It is totally irresponsible for them to have sold you these fish.  You can not combine this much aggression and not have issues.  keep me posted.. dave