I hear ya. But fiberglass is virtually non-porous. As long as the gel coat is in good shape and there are no pin size holes, I should be good to go. I'll probably baffle a few sections off for the skimmer and RDSB and apply another layer of gel coat to be sure it's water tight. Also, since I'll only be partially filling it, the fact that it's above ground and will have no side wall support shouldn't be a problem. I'm gonna clean this thing out today and run a little water test on it.
BTW, I priced fiberglass pond liners like this one and they cost about $750 new. :eek2: