You may also want to try skimmer socks. These are liners which go into the skimmer basket. NOT the pump pot—the skimmer basket. Sold at pool stores, possibly the X-Marts, for around $6.50 for a set of five. They're re-usable.

You put one inside the skimmer basket and fold it over the edges all around, sort of like a coffee filter. The do trap a great lot of debris, including dead algae, pollens, bugs and all manner of other interesting stuff. Check it a couple times each day, rinse it out, replace it.

In the absence of skimmer socks people have used ladies' knee-highs. I cannot attest to their efficacy, haven't used them.

A pre-filter setup such as this can make a big difference when fighting algae.