New pool owner with very high CYA -- should pool be drained?

I just moved into a house in Phoenix Arizona with a pool and am learning how to take care of it, been reading a lot of info here on the site. I'm pretty sure I need to drain and refill but can't do it until the weather cools down. I'm wondering if there is anything I should adjust in the mean time. I have the K-2006 kit, and current levels are:

FC: 32.5
CC: < 0.5
Ph: 7.2
CYA: 400
TA: 130
Calcium Hardness: 750
Water temp: 93 F

Also, with the levels being so high on some of these tests, will it affect the accuracy of the other tests? For example, I read that high chlorine will affect the accuracy of the Ph test but I don't know how to compensate for it. The CYA result was obtained by diluting the pool water with distilled water 4:1 and then multiplying, not sure how accurate that is.

Thanks for any help!

First, don't fix what's not broken. A pool is a swim-able body of water, not a set of numbers.

• Do you have a heater?
• Is there scale build up at the water line?
• Is there persistent algae?
• Is the water cloudy?

If the answer to any of those questions is yes, you may need to drain and refill, at least partially. But:

• Are you under water restrictions?
• Is water extremely expensive?
• Do you have liner or fiberglass pool?

If the answer to any of those questions is yes, you may need to think twice. In particular, you do NOT want to damage your pool by draining.

You probably ought to test your fill water, or at least the pH, alkalinity and calcium. If your fill water has CH=600, you aren't going to be able to lower your pool's CH by a drain and fill.

Regardless, you need to do these things:
1. Get a cheap OTO / phenol red testkit (yellow / red drops).

2. Next time you test, use BOTH the OTO *and* the DPD/FAS to test the chlorine. Note the OTO color. Once you get used to the OTO, you'll be able to guesstimate chlorine levels using OTO, and save some of your FAS reagent, by alternating OTO and DPD/FAS tests. OTO take 5 drops, no matter the chlorine level.

3. EITHER purchase a SWCG *or* start using PLAIN household bleach to chlorinate. You can't use cal hypo without special techniques, because it will raise the calcium level. And you can't use dichlor or trichlor, because they will raise the CYA.

I can't suggest any doses, because you don't include pool size or volume. Also the filter type affects what sort of treatment options you have.

To test your pH, purchase a gallon of DISTILLED (not: spring, bottled or anything else) water. Mix 1/2 cup pool water with 1/2 cup of distilled water, and test the pH of that. So long as the mix water is DISTILLED and not tap water or spring water, the pH will be within 0.1 pH units of your actual pH. When testing pH, use the pH test from the K2006, which is stabilized against high chlorine (though not 32 ppm!), compared to the cheap phenol red with the OTO kit.

For what it's worth, you have the option of operating what I've called a HiC2 pool: high CYA + high chlorine. This method of pool treatment has been used in southern Arizona and California for 50+ years, by companies like PoolChlor (in your phone book, in Phoenix or Tucson), to treat literally 100,000's of pools. These companies inject chlorine gas into the deep end of your pool, 1x per week. The high CYA allows the pools to cycle from 20 ppm after injection to 10 ppm on pool tech return.

Poolstores *HATE* this, because a company like PoolChlor, with 10,000's of pools under contract, can buy chlorine gas by the train car at a tiny fraction of the cost a pool store pays for trichlor or dichlor.

It's not an option for you, unless you have a deep end, since they won't inject a shallow pool due to the chance of chlorine gas escape.

But, the point is, they've proven over a 50+ year period that the HiC2 approach is very practical and swim-able.