Pool uncovered all winter/Ph question

[let_her_flicker]

Have a couple of quick questions:

First tested the PH and it is higher than 8.2 This was taken before I added any Chlorine. Is it possible to get a false high PH? I have added some M. Acid and color changed somewhat (I dont see reds very well).

Next, took Cl up to 20 last night and dropped to 10 by sunrise. On top of the water I noticed a light foam. This started after adding CL to water. Is this something to be concerned about?

I know next year i will start adding chlorine to pool water in February to prevent a green swamp that I currently have. It did go from dark green to an aqua green in one night.

Thanks

[waste]

Have a couple of quick questions:

First tested the PH and it is higher than 8.2 This was taken before I added any Chlorine. Is it possible to get a false high PH? I have added some M. Acid and color changed somewhat (I dont see reds very well).

Next, took Cl up to 20 last night and dropped to 10 by sunrise. On top of the water I noticed a light foam. This started after adding CL to water. Is this something to be concerned about?

I know next year i will start adding chlorine to pool water in February to prevent a green swamp that I currently have. It did go from dark green to an aqua green in one night.

Thanks

Doesn't sound bad to me, there may have been something which raised the pH, but because high cl throws off the pH test, I'd deal with the green first - if you had had low pH I'd have said to wait until the pH was in check before shocking. I've seen the foam, usually with a salt pool and an ammonia algaecide - it eventually clears up. As long as you continue to keep the cl up, the water will continue to clear and, once the 'green' is gone and you can drop the cl low enough as to not interfere with the other tests, you can deal with them then. Depending on your type of pool (liner, fiberglass, crete) and the other #s (alk, cal and cya), it's probably better to have a higher pH than a lower.