I'm in my 7th day at shocking at mustard algae level; +36-41 ppm, every hour, of every day, for 7 days! At last count and this is off the top of my head, it was in the neighborhood of 75 gallons of 6% bleach. 3 sets of DPD titrating reagent and DPD powder, and every day of brushing the pool. My CYA when last tested was 55-60. My over-night FC test is still 2 ppm loss. I've pulled the ladder and thermometer, but can't pull the aqualuminator light. The mustard algae didn't look horrible, just in a couple of seams in the coving on the shady side of the pool. Water has been crystal clear and after the first day the algae can no longer be seen. Been running my pump 24/7 and have a leak somewhere and is putting bubbles into the return, so I have no idea where my PH is. Going into this I knew my PH was nearing the high-side, around 7.65ish, so after a week of blowing millions of tiny bubbles from the return, I arbitrarily added 1/2 gallon of MA, knowing the PH had to be up.
Anyone have any thoughts? I'm sure I'm bleaching the liner by holding my FC level this high, and don't want to win the award for longest battle with mustard algae. Last test of the day is at 9 and first test is at 6 before the sun comes out. I'm using a 5 ml sample of water because I cannot distinguish a 10 ml sample when testing, as the sample turns from a very light pink to very light orange, never clear. I'm assuming because the FC is so high. I know the 5 ml sample is not as accurate, but it gets me close enough without having to buy 3 more 2 oz bottles of reagents. I test and add every hour until I have to go to work at 2, and then at 4 my wife takes over. Don't know how's she doing, but every night I test when I come home at 11 and the sample she's drawn at 9 tests out to around 41 ppm, so I'm assuming she's on schedule.