I'm looking for some input as to why algae keeps reappearing after Slamming and successfully completing OCLT. This has happened twice now and I'm puzzled why this is happening. Thanks to this forum I had an algae free season all last year and want to have a repeat this year. After performing the SLAMMING and OCLT the FC has constantly been in the range of 3-7 ppm and CC is 0.5 ppm or less. The water is crystal clear but green areas keep appearing on the floor and benches after about a week of completing the SLAMMING process and OCLT.
Chemical Levels as of this morning are:
Calcium Hardness: 225 ppm
Total Alklinity(60-120): 75 ppm
FC: 5.5 ppm
CC: 0.5 ppm
I have a UV light that I thought maybe driving down the CC and giving me a false positive on the OCLT. However, I disconnected it on Sunday (6/21) of this week and I have not seen an increase in the CC over the last 5 days. I have not SLAMMED the pool since disconnecting the UV light because I wanted to see if the CC would increase without the presence of the UV light. Any input or ideas is much appreciated.