We have a few deferred maintenance projects in our 1950's era fiberglass IG pool - the fiberglass has some chips and cracks and some of the tile grout below the waterline has been eroding away. So after a lot of bleaching, brushing, and filtering to get our pool looking algae-free with nice clear looking water and a FAC of around 5, I still see what looks like green algae hiding in the eroded tile grout and mustard in the fiberglass chips along the waterline. Any suggestions for keeping these things in check until we get the fiberglass and tile issues taken care of - I've brushed out the grout with a bleach-soaked old toothbrush before but am afraid I'll end up eroding away more of the grout.