I purchased two sucking loach fish from Coventry Gallagher pets at home - did the acclimatising correctly as you do ... my tank had been set up with 4 fish in before hand completely fine for a few years ... after adding the fish correctly for an hour or two they were okay darting round the tank swimming eating etc . My brother came round and noticed they were acting a little strange ... swimming up but floating back down like they were lifeless ... we decided to examine the fish to see they actually had white spots over their bodies ... now we would have got them checked but this was after stores were closed. However they didn’t make it 4 hour after purchasing these fish they had died ... cleaned my tank removed them and added all fresh water ornaments and gravel along with my 4 fish I had to start with years ago... all well and good until I woke up this morning popped to the shop and one of my black moors had passed! What the hell had pets at home fish got wrong with them to kill them selfs along with my beautiful fish