How could the cya drop from 53 to 5 in 6 days. Shocked pool and added 15lbs hardness increaser to raise calcium. Made no other adjustments and all chlorine levels went to 0 as well. Does this make sense.
CYA
- Thread starter csmdew
- Start date
Tell us how your testing and lets have a full set of test results like
FC
CC
PH
TA
CH (not so important)
CYA
FC
CC
PH
TA
CH (not so important)
CYA
Here's last week and this week: FC .06, CC .02, PH 7.9, CH 99, TA 80, CYA 53
.00 .00 7.6 168 68 5
These were done using HTH testing machine at local ACE hardware.
.00 .00 7.6 168 68 5
These were done using HTH testing machine at local ACE hardware.
Test strips are imprecise and unreliable. That goes double for test strips read by a machine. And this is exactly the problem, you get impossible results. This is one of several posts currently active about test strips giving results that claim an impossible drop in one level or another. You really need to consider a more reliable test kit: Test Kits Compared
On a separate note: vinyl liners don't need a specific CH level. You didn't need to add calcium any to your pool.
On a separate note: vinyl liners don't need a specific CH level. You didn't need to add calcium any to your pool.
- Mar 5, 2020
- 3,221
- Pool Size
- 66000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Astral Viron V35
The only way for CYA-levels to come down quickly, are certain soil bacteria that turn CYA into ammonia. For that to happen, FC needs to be be low for a longer period. It is more likely to happen over winter when the pool is closed. But it can also happen in summer when FC is allowed to stay low.
The ammonia will react very quickly with chlorine, building up CC. Ammonia will consume all available chlorine until all ammonia has been converted to CC.
The indication for that is an unexpected drop of CYA and not being able to raise FC despite adding large amounts of chlorine. CC will rise.
Do you have a proper test kit with FAS-DPD to measure FC? This is essential to do a proper diagnosis. Don't add any CYA until we understand what is happening.
The ammonia will react very quickly with chlorine, building up CC. Ammonia will consume all available chlorine until all ammonia has been converted to CC.
The indication for that is an unexpected drop of CYA and not being able to raise FC despite adding large amounts of chlorine. CC will rise.
Do you have a proper test kit with FAS-DPD to measure FC? This is essential to do a proper diagnosis. Don't add any CYA until we understand what is happening.
- Mar 5, 2020
- 3,221
- Pool Size
- 66000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Astral Viron V35
No test strips were used, water analysis machine is what the store uses and sure that ammonia was not put in pool during that 6 day period. I've been using a poolmaster 22260 test kit. The chlorine was good on friday and gone yesterday. Makes no sense.
Reread what Donldson is saying in his post to you. We have 13 years of experience and a quarter of a million posts on this forum and one of the most prevalent issues is bad pool store testing........regardless of how it's done.
Your test results actually make perfect sense once you determine they are totally unreliable........and they are. Sorry.
Your test results actually make perfect sense once you determine they are totally unreliable........and they are. Sorry.
My mistake, I was thinking a different HTH store test. Let me correct that:
There, thanks for letting me clear that up. BTW, the Poolmaster kit is not very good. The pH test is only accurate when the FC is below 3, the OTO test isn't precise at all, and you lack both a CH and CYA test. The latter of which is vital to proper pool management.
Doing search for top rated test kits online came up with that one as the best or in top 3 from at least 5 sites, so I bought it. Had no problems with anything until these tests were done so you may be right, how ever using the kit and test strips as well and I now get about same results as the store's results. Just don't know how it could have gone so bad in one week.
Wasn't arguing with anyone, just trying to explain how test was done and wouldn't be asking if I knew what problem was. Need to know what I should start with at fixing the problem.
I hope you have the time to continue to search and read here on pool store testing.........thousands and thousands of members just can't be all wrong.
Let me say it another way. If pool store testing was at all dependable and their advice really good, TFP simply would have no reason to exist.
Accurate test results. Without results we can trust we can't help you, and the ones you have now only seem to be causing you endless confusion.
Step 1 of fixing the problem: get a Taylor k-2006c or TF-100. Once you have that you can post up the numbers and we can help you determine what, if anything, is wrong with your water.
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