Those of us who use skimmer socks swear by them. They catch all of the small stuff which would normally get sucked through the basket holes and clog up the filter medium. I've had to backwash my filter much less often and, when I do backwash, the output is much cleaner.

But there is a drawback: The skimmer sock will retain some algae cells. It's just the nature of things. You can rinse off the large bits, the dogs hair, the bugs, but rinsing won't dislodge all of the "live" contaminants.

If you, despite your very best efforts, continue to get algae growth, it's possible that the reinfection occurs via the skimmer sock. I've begun to soak mine in a strong bleach and water solution, a 1:1. I keep the sock over the basket when I vacuum my pool and the crud caught in it is awesome. Disinfecting the sock makes sense to me. We shock our pools. Why not shock the sock?