High chlorine is a relative term! It's all dependent on your CYA level. But, algae can grow a biofilm that protects it from chlorine. That's why we suggest a good brushing at least once a week. Everyday, if you're SLaMing.
FYI - I see your signature. It says: Laurie - Houston, TX 12000 gallons, Saltwater, Hayward Pool, pump installed by unknown 2011, ProLogic
FYI - I see your signature. It says: Laurie - Houston, TX 12000 gallons, Saltwater, Hayward Pool, pump installed by unknown 2011, ProLogic