Hi everybody, I'm a newbie and this is long.
Saltwater Intex pool, 3200 gallons, in the shade. Second year, this year we put a 12X12 canopy and mosquito netting (they're fierce) which keeps most debris out (but daddy long legs still get in...)
Last year we had no real problems other than keeping stuff from the trees out (hence the canopy). Used Intex and HTH test strips all summer, added AquaChem shock a few times (half a bag at a time, max) because of the tree debris but didn't seem to have any water chemistry problems other than the pH ran around 7.8-8.2 (I know why now).
Like last year, I try to vacuum every 3-5 days and change the filter about once a week, we get a good bit of sand blown in. We got the salt right at the beginning and added the HTH stuff for starting SW pools for CYA/cell maintenance as we were filling.
This year - started out OK but after the first week I began noticing this strange white stringy waxy stuff in the water in mid-June. Brand new pool liner (last year's was punctured with tree branch from H. Isabel).
I thought it was white mold, so I searched the internet then added about 2-3 lb of HTH pH Minus to bring the pH down (8-8.5 with test strips and I was following package directions) before trying to shock the pool.
The pH dropped to under 7 so I guess I added too much, but there was no new white stuff. I added 1 lb bag of AquaChem Shock Ultra (orange bag) from Wal-mart to kill the white stuff and added a few inches of fresh water to try to bring up the pH.
A couple weeks went by, we had some storms and didn't use the pool much but by the end of June the FC was showing as 10 or higher on the strips, the pH was creeping up again to 8, the TA was 40. TH and CYA seemed ok so I tried more water and 3-4 lbs pH Minus. This time I think I added way too much! I wasn't seeing any more white stuff but was starting to see some brownish slime on the strainer that was hard to scrub off (no where else though). I had been adding HTH Natural Clarifier for floccing but saw somewhere that that was not a good idea so I stopped.
The pH dropped to under 6.8, TA 0-40, TH 100-200 and CYA 0-30 with test strips. So I added 1.5 lb stabilizer to bring up the CYA. This was July 2. From then to about the 8th the pH was still low and the FC was staying at 10+ (very dark purple on the test strip) so again I added water and about 1 lb ph Plus this time.
I also bought an HTH 6-way drop test kit on July 11. It said my combined cholorine (OTO test) was out of range (very orange), and the test strips still said 10+. Red phenol pH 7-7.2, strips a little higher. CYA drop test 90-100, strips 50-100. The TA and TH tests were wacky because the colors didn't match the instructions (and still don't today) but I think TA 40-80 and TH around 100.
Our weather has been very hot and dry for a few weeks now, several days in 90's up to 100 and lows in 70s (mid-Atlantic). No rain in forever at our house. We use the pool about 15-30 minutes a day almost daily but not in the past week. Pump runs 24 hours/day since opening, SWG 6 hours daily.
Water getting a bit of a green tint. Copper readings using Intex strips staying 0.2-0.5 since opening. Changed filter as usual and this one had bluish-green color for the first time.
Then I found this website and poolcalculator.com. I read several sites about what levels for SWG should be, put in the numbers and my data, added half a jug chlorine bleach and a 1-lb box of baking soda (all I had at the time) per instructions. Yesterday I bought new test strips since mine were from last summer, checked again with test strips because I was too busy to do full drops and the pH was up again so I added about one lb pH Minus.
Pool looks fairly clear but now has a greenish tint. Second filter switch out and it is blue-green again. Reminds me of copper from chemistry classes but pool is starting to smell bad. I see nothing in the pool but the usual bottom debris and DDLs. I examined SWG and see scale formation.
I am convinced I need a Taylor kit and am going to find one.
Data this morning using my stuff on hand:
HTH strips Intex strips HTH 6-way drops
FC 10+ 5-10 CC >5 (OTO) very orange
pH 6.8 8-8.5 7.2 (red phenol)
TA 40-80 100-150 40? (blue rather than green -> yellow but not red)
TH 100-200 150? (yellow -> light blue)
CYA 50-100 100 (black dot)
Salt 6.4 -> 3130
Pool calculator says I should add some more washing soda or borax (I have HTH ph Plus) and about 1-1/2 boxes baking soda, also I should drain about a quarter of the water and add fresh to bring down the CYA.
What I don't get - why does the FC stay so high and how do I bring it back down?
Should I drain some water out of the pool, add fresh and go from there?
Should I shock the pool again, and is the orange AquaChem ok or should I just add plain chlorine bleach?