First things first, I suppose - current test results, as best I can get them.
FC: >5 ppm
TC: >5 ppm
TA: >500, though the folks who sold me the test kit said that this was unreliable if FC is >5. I suspect pH would be a lot more alkaline than 7.8 if this were true - am I correct?
CYA: My kit doesn't have it, and neither local pool store will test it with FC >5.
CH: As CYA.
And I did put this in my signature, but it's a 20k gallon in-ground gunite pool with a DE filter. Due to surrounding house and trees, it doesn't get a lot of sun - a few hours around noontime, mostly.
We bought our new house with a pool. We were told it had not been opened or the pump turned on for 3 years, but they opened and cleaned it up for our inspection. Seemed mostly fine, though there are some cracks at the waterline and it needed a new pump.
This season (our second), we started to see some greenish brown stuff on the walls and bottom (there was a very little bit of it last year, but not enough to make me think anything of it). The vacuum does nothing, a (nylon) brush will take it mostly up but "puff" it into the water. For reference, we just got back from a week-long vacation and by the time I'd brushed half of the pool the water was opaque green. I'm attaching a pic of our steps shortly after brushing today - the overall green tinge is the color of the water immediately after brushing when the previous brush was two days ago. The mottling is on the gunite. Even at its worst, it doesn't feel like anything when touched - just the gunite.
Being naive new pool owners, we went to the better-reputed of the local pool stores to ask for advice (mid July). They said it couldn't possibly be algae with chlorine levels that high (quoted at the time as "off the charts" which I'm guessing is >5 ppm since they use the same kit I have for in-store testing) and it must just be pollen (our lot backs up against some woods, mixed pine and oak for the most part). We were told to stop using powder and turn off the chlorinator for at least two weeks, then turn it back on at the lowest setting, so that the chlorine would drop to a proper level. Afterwards, the problem was much more widespread. They also said to run the pump 24 hours a day instead of the 8 recommended by the folks who installed it, which we've been doing since then.
Then we went to the second local pool store to see what they thought. These folks said it looked like algae to them, and on their advice we put two bottles of non-copper algaecide in (~50 oz). Didn't do much. Then they said we'd have to crank the chlorine levels way up; this month we've used most of a 40 pound bucket of chlorine tabs and a 24 pound case of powder. This also didn't do much.
Now the second store is saying that we'll have to, every day, use a bunch of "chlor away" to get the levels down to a testable range, then add a big pile of powder to get the level back up. Preferably twice a day for at least two weeks. A bit of pricing out suggested this would cost ~$150/day in chemicals.
At that point we concluded there must be a better way, started doing some research, ended up here, and read Pool School. I've just ordered a TF-100 XL and bought about 6 gallons of 6% bleach. Our intention is to follow the program in the "defeating algae" Pool School article once the kit arrives. (I'm assuming we need to get this under control before closing or it'll be completely berserk next season.)
So that's the situation. Now, the questions I have:
1. Does this sound more like algae or pollen?
2. Are we on the right track?
3. What sort of quantities of bleach should we be expecting to use?
4. Am I correct to be afraid that our CYA level is through the roof?
5. Any other tips or suggestions?
Any input will be greatly appreciated.
P.S. Due to the aforementioned cracks (and consequent loss of tiling), plus shifting of the surrounding deck due to dirt settling, we've been quoted $20k for draining the pool, fixing up the deck, replacing the tiles, and resurfacing the inside. This supposedly needs to be done in the next 5 years or so. I may be getting overly paranoid here, but I do assume this process will eliminate the algae (and by draining the pool, reset the chemistry esp. CYA). Should we be considering just closing the pool for the season, and doing that work beginning of next season? Or can the situation be salvaged with less drastic measures?