So last night I stopped off and bought a few cleaning things to try. Here is the run down
Magic Erasers - zipppo, nuttin, nada. Zero effect on hard water stains
Kaboom - did some cleaning, but only when scrubbed in with a stiff bristle brush. Left quite a few very tough areas.
SOS pads - nuttin.
Lime Away - got rid of most of the rest of the really tough areas, again only with a stiff bristle brush.
Still might try some Oxy Powder stuff I saw. Still looking for the spray on, rub with a sponge miracle!! Also recommended by a co-worker. Local Orchard Supply Hardware has a specific cleaner made for fiberglass.
I need to buy a water softener, but I just don't like the way that stuff feels.. ick
Thanks for the suggestions everyone.