CYA 10 (per pool store. Couldnít register it on mine and I am currently adding stabilizer using sock/skimmer method)
I cannot get rid of my green stuff. Pool calculator says shock level is 10 and mustard algae is 12 which I tried for a couple of days and now Iíve had it at 15 for 48 hours. Before starting the shocking process I added FC each morning to bring it to 6 and it is usually 2.5 Ė 3 the next morning with only .5 (or 0 a couple of nights) for the week leading up to the SLAM. I have never let it get lower than that so Iím confused as to how I got algae in the first place. What I have is a slight green ďsettlingĒ on the bottom of the pool that accumulates in the wrinkles and low spots (darn gophers!) even though I havenít turned my pump off in a week. You almost canít see it until you brush and the liner looks bluer underneath it and you get a small green cloud. I understand it takes a while for the filter to get it but shouldnít all the chlorine be turning it something other than green? Iíve also been adding DE to my sand filter each time I backwash. The condition above hasnít changed a bit in 4 days Iíve been doing this (returning it to shock levels several times during the day, too, as well as after the sun goes down). Its not even noticeable until you brush. The water looks clear but not sparkly. Nothing growing on sides and settles back down pretty quick after a brushing (which I am doing daily or more). Lost 1,1, and .5 ppm the first three nights of shocking but last night it maintained the 15 FC overnight.
Needed stabilizer so took a sample into the pool store just for kicks. Their numbers were so different it was alarming but Iíve got a K-2006 so I feel confident in all the numbers above except for the CYA. It was running at 30 all summer until I left the water running too long and overflowed my pool for about 30 minutes about 2 weeks ago Working on getting it back up and not confident it is as low as 10 but shocking over suggested levels even for a 20 CYA. Pool store did say my phosphates were really high (1000) and again I read that shouldnít be an issue if I am keep safe levels of chlorine Ė which I am.
Iím getting pretty discouraged -- for such a small issue not to be seeing any changes when Iím shocking several times a day over suggested levels. I have read and re-read pool school and SLAM. Donít want to damage anything and what Iíve read says you should only run it at higher shock levels for a day or so and Iíve already done it for two. Where did it come from and how do I make it go away? Any suggestions would be greatly appreciated!