CYA reading-it's way high!

[SAPoolOwner]

I'm just getting started with the BBB method and after obtaining a good quality a good quality test kit I have the following
FC 2.0
PH 7.4
TA 140ppm
Calcium 550 ppm
CYA approx 400--really don't know off the scale just an extrapolation.

Everything I have read the only way to lower the CYA is to drain and replace. The question I have is that by starting the BBB method and not using a stablizer will the CYA eventually come down byt slpash-out and evaperation replacement or should I do a drain and replace?

Thanks.

 

[JasonLion]

CYA will come down very slowly over time if you stop adding it. It your CYA level was 90, waiting for CYA to come down might be a reasonable strategy. If your CYA level is actually 400, waiting for CYA to come down will take years and years and there isn't any practical way to manage the pool in the mean time.

You should get your CYA level under 100 by water replacement and then let it go down more slowly from there.

 

[JohnT]

Evaporation won't affect CYA. Only splash out and water replacement. The CYA test is not linear, so extrapolation of the test is tough. You can try diluting the water sample with distilled water 50/50 or 25/75 and multiply accordingly to get a rough result. Be aware that any cloudiness in the water will skew the result higher. You also have high calcium hardness, and this also merits draining some water and replacing it if your fill water has a reasonable CH level.

With a cartridge filter, normal water replacement slows down since you don't backwash.

 

[HarryH3]

Pete, I had to do the same thing to my pool last spring. I made up a manifold to fit a shallow well jet pump that I keep in the garage, which let me connect garden hoses to the pump and spread the pool water onto my lawn.

I borrowed enough hoses at fill time to run hoses from 5 different spigots on my house and was able to fill my 26K gallon pool in right at 24 hours. 8)

The good news is that it was FAR easier to keep my water clear afterwards.

 

[frustratedpoolmom]

Drain and replace. If the CYA is really 400 it will probably mean 3 or 4 partial drains/fills before you get it to a manageable number. Drain 1/3, fill....test. Add chlorine if your fill water is not chlorinated. Repeat. Test again....My CYA is the same as it was at the end of last summer, after 2 partial drains/refills. It did not go down much at all, it's about 60-70 but I'm dealing with it....