First off I want to say that this is a great forum and website. I've learned quite a bit from reading this forum and pool school.
Backround; pool and equipment are 9 years old. I purchased this house a month ago and have never owned a pool before. I expected a learning curve but everything went too smoothly at first. The pool was opened the begining of June by a pool professional. The pool was covered and the pump was running 24/7 until 6/24. 6/15 was the first time the pool was used and it looked great. 6/23 moved in and the pool has been used ever since. The pool is covered when ever not in use. Using the basic test kits for readings I added chlorine sticks to keep the level around 5 ppm. I had the water tested at a local pool store and was told everything was fine except for PH at 6.8 and CYA at 170. I was told to monitor cya to see if the results would remain the same and add PH up to increase Ph to 7.2. I adjusted the PH and ordered a TF-100 test kit.
7/13 first test PH 7.2, FC 5.5, 0 cc, TA 150, CH 170, CYA 100. I wish I knew then what I know now. Pool is still perfectly clear.
7/14 Added Algaecide as a preventitive measure. I used Dupont's dimethly benzyl ammonium chloride. I didn't know of polyquat 60 then.
7/15 In the evening the pool was not as clear as normal
7/16 Opened the pool to see it cloudy and had 0 FC. I started reading more here, added 9 gallons of 6% bleach and closed the pool. When I opened it in the evening yellow algae was floating on top. Added more bleach to reach regular shock levels.
7/17 By the end of the day the pool was back to being cloudy with no vissible signs of algae. In two days I had used 34.5 gallons of bleach. I wish I had pumped out half the water in the begining of June to have a manageable cya.
7/18 and 7/19 Chlorine continued to be consumed but at a lesser rate. I used 9 gallons of 12.5% clorine trying to maintain FC greater than 25 on theese 2 days. My cc consistently held at 1ppm. The water looked pretty good by the end of Thursday.
7/20 My oclt was 10 (31 down to 21). I added DE to my sand filter, ran it a couple of hours until skimmer flow was low, back flushed and repeated a second time. By the end of the day I added water, used 3 gallons of 12.5% chlorine and the pooled looked great but ...
7/21 oclt was 7.5 (31.5 down to 24) The water test result first thing were PH 6.8, FC 24, CC 0, TA 180, Ch 170, CYA 90
7/22 Still at shock level. 3 gallons of 12.5% added
7/23 oclt at 3 (26 down to 23) cc at .5. 2 gallons of 12.5% added through the day. Pool looks beautiful and feels squeaky clean.
7/24 Oclt at 3 (26.5 down to 23.5) cc at .5. I removed the light to find some dead algae behind it. Other than that everything looks and feels great great.
My question is this, How much longer should it take until my oclt is below 1 and should I go to the mustard algae shock of 49 now? I have not raised the PH yet because I would like to lower my TA and add borates.
Any help or comments would be appreciated. Sorry for a long first post but I didn't want miss anything. Also pool temps have been 89-96 during my problem.