[mpprh]

I have a fibre glass shell pool and a fibre glass boat.
Both have small blisters in the gel coat !

I see that there is no agreed advice on a remedy for this within the pool world.

The boat people know more about this, so it is worth reading up the treatments they use .......... and those they don't use now because they only have a limited effectiveness.

Type boat osmosis into google to read all about it.



Peter

[AquaclearNZ]

i have a couple of well proven ones from the last few years, however while they will get rid of the black spots you are still left with a clear lump under the gel coat - after treatment keep your ph around the 7.0 - 7.2 mark

sodium metabisulphate works as does lo-chlor stain remover #1

check out lo-chlor.com for more info

i have sold both for 15 years, #1 works every time and is ph neutral, so easier to rebalance

however in full fairness - your pool surface is looking pretty screwed