Hi! My wife and I bought a house last month that came with an appx 30,000 gal 20x40 plaster in-ground pool with a sand filter. The prior owner had recently shocked and FC was still at about 10 ppm when we moved in, which seemed high, so I stopped adding chlorine and let it drop down to around 2-3 ppm (this took awhile since the pool had a solar cover on it and we weren't using it much). Unbeknownst to me the pools CYA was in the 160-170 range (prior owner used chlorine pucks), which now that I've discovered this site I understand means I should have left the chlorine levels where they were (or higher). Combined with storms/leaves in the pool last week, long story short I got my first algae bloom a few days ago.
Came to this sight (having discovered it a few weeks ago) and read about the procedure for slamming the pool. Broke out the test kit I had ordered a couple weeks back and realized the high CYA was probably where I went wrong and would also mean that slamming the pool would require a huge amount of chlorine unless I could lower CYA. To lower CYA I drained and refilled about 70% of the pool. Fill water came from our well. As I was refilling (took a couple days), I was adding bleach to raise to shock levels (trying to hit something of a moving FC target as the pool refilled). Been at shock levels for about two days now.
This is where I'm currently at:
Ph: 7.2 (I believe...can't reliably test anymore due to high chlorine, but the pool water was 7.2 and the fill water measures 7.2 also)
Water seems to have cleared a little bit (can now faintly see the drain at bottom of deep end) but still pretty green. Also, while adding water there was a decent bit of brown sediment settling at the bottom of the pool (iron from well water?). It seems to have dispersed some from running the filter but I can still see sort of a haze of brown dust collected along the walls in the deep end. Filter and polaris have been running for about 48 hours (without skimmers because water is still below the skimmer line).
Right now I'm kind of at a loss what to do next. Was scheduled to have someone come close the pool today but this development obviously threw a wrench into things. When the pool guy came out this morning he said the algae should already be dead from the chlorine and that the iron from the well water appears to have oxidized (turned brown) from the chlorine and to just turn off the filter and let the sediment collect at the bottom and then he'd come back tomorrow, sweep, and then close the pool. I'm a bit nervous about closing the pool the way it is without clearing the water first, dealing with whatever the well water may have introduced to the water, etc, etc, and feel like maybe I should delay another week but at the moment the plan is for him to come tomorrow morning to close unless I tell him otherwise. I feel like I'm asking for trouble next spring if I close the pool as it is...Am I being paranoid?
Any advice would be much appreciated, and thanks in advance!