I am a relatively new pool owner(pebbletec), and with these super hot AZ days we must have let our FC drop too low for our CYA level, and now have a few black algae spots on the bottom of the pool. We used a pool pumice to scrape them up & began the shocking process with liquid chlorine last night. My concern now is that the waterfall seems to have been the source. The boulders at the base of it were growing with algae. The problem is that part of the area is not always submerged, and the boulders have nooks and crannies that are hard to brush with a steel brush, and even a chlorine tab. Any suggestions on eliminating all traces of algae in those hard to reach places above the water line so we can avoid reintroducing algae after shocking?
I have read to frequently clean the filters during this process, yet the pump must run 24/7 We have cartridge filters. Should I just clean them when the shocking process is over, or would it be better to turn the pump off for a couple hours to thoroughly clean the cartridges?
CYA has been difficult to pin down. Leslie's always came in around 70-90, but home test showed 60. I think I may have been doing it incorrectly, and my recent test (while shocking) showed 45-50. We dropped the PH to 7.2-7.4 last night, but this morning we have TA 90, CH 360, FC 27.5/.5CC...too high? Damage?
We also have a regular problem with PH rise, possibly due to SWG with spillover/water features. I have yet to understand how PH impacts algae growth, and whether borates would be beneficial for us. We readily climb to 7.8 and have to add acid to get it back into range. I realize this is a different issue, but any advice is greatly appreciated. I'm still trying to get my bearings with all of this & ironically I thought I was doing a pretty good job - ha, lesson learned!