FC/CYA Test
The shock levels shown have equivalent effective disinfecting chlorine amounts. At very high CYA levels it can be impractical to reach such high FC levels. At CYA levels over 80, a partial drain/refill to lower the CYA level is usually required before you start the SLAM. Most saltwater chlorine generator (SWCG) pools appear to remain algae-free at a lower minimum FC level compared with the minimum FC column for manually dosed pools. This may be due to the high chlorine level within the cell. For indoor pools we recommend CYA between 20 and 30ppm. The …