If you put about 1/4 cup of DE into the skimmer and it doesn't shoot out of the returns, you know your filter is working, and will eventually get the pool cleaned up. The DE will help your filter work better, but you'll have to backwash more often. I always add a little DE to my skimmer after I backwash. Also, if the water is clear enough that you can see the bottom, it's fine to go swimming. Dead algae is harmless to people and keeping it stirred up helps get it into the filter. Just be sure you can't loose sight of someone in the cloudy water.

Pappy