Have had my premium Leisure hot tub just on two year when my wife was changing the water and
we seen these blisters and two with holes in them.
the dealer email premium leisure about this and was told the warranty limitations and exclusions
which made it as cheap to forget about it and by a new one.
This problem with the Acrylic has to be with the manufacturer and its materials or workmanship.
I have read review by other people with the same problem so think twice before making up you mind
on one of these premium leisure hot tub.