Baby BN pleco dead :(

[Tleyton]

Just got a baby BN pleco (1 inch max) on Thursday. Was doing wonderfully. About 2 hours ago I noticed he had a bloated stomach, but he has been eating non stop since I bought him and was wedged behind my heater. I nudged out from behind the heater and he swam away normally. Not but 30 mins later was dead at the top of the tank. I have a 55 gallon, ammonia 0, nitrites 0, ph 7.6, nitrates 5. Housed wih 4 Corys, 7 guppies, 1 Molly, a mystery snail. I do add aquarium salt 1/2 tablespoon per 10 gallons. Any ideas? Just want to make sure it wasn't me. And he did have driftwood to eat.

 

[Tleyton]

Oh dear...just read an article about aquarium salt and scaless fish...I think I killed it with salt.