Watermold does take a lot of bleach for a long period of time. Just remember to keep it at shock levels continuously - I would take it higher than shock level if you can't test often. The more vigilant you are now, the shorter the time to clear the pool. By the time you see the tissue like strands that you described, you have a pretty good case of it and you have to use a lot of chlorine to get rid of it. It also takes a while after it is dead to clear out. Don't get discouraged - just keep up with the bleach