From my understanding fiberglass pools are not affected by high chlorine levels. In fact, my builder used straight 12.5% chorine to get some organic stains off the surface while mine was being installled. Don't know if that was good or bad but it didn't hurt the pool at all.

If you have no CYA then that level might be a bit high but if you have high CYA then that level is not high enough. See this thread for details
http://www.poolforum.com/pf2/showthread.php?t=365