Greetings

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OK.

And again, upfront - thanks for everyone's good help. I will certainly post final actions actions to this case.

10pm last night: 5.2 FC & 0.4 CC
5:30am this morning: 4.6 FC & 0.4 CC

On Monday the 11th (mid/late afternoon) the FC ~9.0.
Today Thursday the 14th w/ the FC ~4.6.


So bottom line: #'s 1 & 2 below is what I really need help with. The rest I just need to decide what to do when & how.


1.

  • OCLT drop was 0.6 FC which I believe is within acceptable limits.
  • In 2 1/3 days the FC dropped 4.4ppm (~100 degrees full sun with some minor leaves blowing in. No swimming).

I'm assuming the high CYA would just make it impractical to keep FC at a commensurate level as it would take too much chlorine each week to get it in range? And that range would be somwhere in the "teens".

2. Considering #1 above, is a CYA level of 160 harmful in any way? Probably just very impractical as cited above?

3. yes, seems I need to bump up PH a little (7.3 now)

4, Ak needs to be reduced from 350 to about 90

5. CH is high at about 900. Doesn't appear harmful but should be reduced to more tolerable levels.
 
Supposedly reverse osmosis can remove CYA from water, it's probably expensive. I just googled "Woodland Hills, CA reverse osmosis" and had a couple of results come up.

Let us know if you go down that path, don't hear about people doing RO that often.
 
Just summarizing options... assuming pool is clean, based on passing OCLT, no visible algae, CC's normally 0.0 to 0.5, and water is clear

As some people here have done, continue at high CYA (160), let it fall from rainwater removal and splashout, could take all next year in a dry climate. CYA does degrade, albeit slowly.
- be sure of your CYA test result with a careful dilution test (I prefer a larger dilution quantity, some use the pH test tube, some use 2 cups of pool water to 2 cups of tap water, etc., draw CYA sample from the carefully diluted 1:1 mixture)
- Use bare minimum 12 ppm FC and target of 16 ppm FC
- pH will be inaccurate above 10 ppm FC. People managing at high CYA dilute the sample with good quality distilled water (e.g. from a pharmacy) to get below 10 ppm FC (acid and base demand tests can not be performed; mentioned here but not an approved method)

More people are going to recommend reduction of CYA to 80, i.e. 1/2 the water exchanged, to put it behind you. The side benefit is reduction of CH so you have headroom there. You've mentioned 600 ppm CH (manageable) and 900 ppm CH (still manageable but getting closer to difficult). If there is any chance that the pool needs a SLAM now or within the next 12 months, I think this is the only practical way to go. Some jurisdictions set sewer rates based on winter water use, so you don't want to end up draining if within that sort of window. There's 5 ways to do this.

1. reverse osmosis - expensive, little owner time
2. drain the pool down half way, then refill - plaster is dry for some period of time; pressure from ground water can lift pool; vinyl liner risks, etc.; simple and reasonably predictable
3. partial drain / refill, repeat as needed - reduces above risks a little, uses more water, reasonably predictable

Can't call these approved methods here:
4. fill at bottom / drain from the top - less predictable; works only if pool water is substantially warmer than fill water; eliminates above risks
5. tarp with fill water on top and waste water removed from below tarp - some say this is used by reverse osmosis companies, and some say it doesn't work; eliminates above risks

If you want any more info, let us know and we can refer you to other threads for more detail, or try to answer.
 
OK. Back from vacation and wanted to say thanks to all that were kind enough to assist me.

Drained 4/5 of the water from the pool and refilled about 3 weeks ago. Now: CYA down to about 45ish. Much easier to keep FC in the pool, CC down to darn near zero. pH maintained at 7.4. Calcium still high (700) but I'm told it's a local water thing. Of equal importance - I installed a backflush valve. Previous PM guy never said I needed one. I think that in itself will assist with maintaining levels in the long run. Water is sparkling and so far relatively easy to maintain. Looking forward to a remaining Fall Season Trouble Free Pool :?)

Regards to all.
 
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