What is Black Spot and howdo I treat it?
First establish that’s what it is Black spot algae is small to medium raised spots, some as big as your thumb nail and it’s actually dark green when you scrape it off with your finger nail. Sometimes it’s confused with Osmosis which only occurs in Fibreglass pools where as Black spot algae only occurs in Pebble & Marble interiors, slate steps and waterline tiles. Treatment: Walls and floor or in tile grouting • Turn salt chlorinators off till the next day for this treatment. • Dilute and add 200mls Hydrochloric acid per10,000lts, run filter 1 hour. • Add 1lt Liquid Chlorine per 10,000lts, run filter 1 hour. • Dilute and add 200mls Black & Tan Algaecide per 10,000lts, run filter 2 hours. Treatment: Floor only • Turn filter off and sprinkle 400gms Stabilised Chlorine per 10,000lts over spots, allow to settle for 2 hours then scrub using stainless steel algae brush. • Note: For bad infestations do both the above treatments. Treatment: Step areas • Turn filter off and sprinkle 200gms PQ gr
