I have a 6 or 7 inch common pleco in my 20 gallon platy tank....i would like to move him into the 55 gallon if possible but i dont want to kill it because it was one of the first fish i got....the green spotted puffers are in that tank now, two of them about 1"....there is some salt but very little the specific gravity is about 1.06 which is almost the same as the platy tank. is this possible to do? I think the pleco would be a lot happier in a bigger tank.