Hey guys! Okay, so i have this young guppy, about 6 months or so now i think, he was given to me as a tiny fry accidentally in a bag of guppies i got from my local aquatics shop. He did really well, quite brave and friendly. But i had fin rot/pin tail sweep through my tank rapidly and kill off most of my guppies (Even with treatment and segregation). He however, survived and looked completely healthy. But over the past two to three weeks, he's stopped swimming, he just slithers along the bottom of the tank. Finds his favourite plant and just chills under it's big leaf for a while. I've done water changes, treatments etc. I even completely pulled apart my 100ltr tank and replaced absolutely everything. (using filter media from my other healthy tank) But nothing, he still lies there looking sad and lonely. Over the past couple of days he had one or two occasions where he did swim up and met with all his friends for a few seconds but then just sinks back down again. In a last ditch effort, i have set up my very old Fluval tank as a hospital tank and put him in there. Starting a new treatment. But i worry now that with no friends to even very occasionally swim with, he'll get worse. Help? Advice? I'm losing my mind!