It's really hard to tell the difference between the pollen and mustard algae....after pollen has been in the pool for awhile it tends to turn brownish, so what you have in the second layer may just be pollen that's been there a few days. The best way to tell if your chlorine is holding is to measure your chlorine in the evening after the sun is off the pool, then measure it again in the morning before the sun hits it--that way any chlorine loss is due to organics and not sun exposure.

the pollen around here is horrific this year, too--increased filter time will help.

Janet