Unable to keep chlorine level and CYA level has dropped from 38 to 21 in 1 day.

[lizbyrne2000]

Unable to keep a chlorine level in my pool. Shock it again yesterday and my reading is zero. My CYA level dropped from 38 yesterday to 21. Pool store thinks I should use a phosphates remover. But the pool is clear and blue after I had to remove the iron that had stained my walls and steps. My ph is 74 & alkalinity 108.

[PoolDoc]

My CYA level dropped from 38 yesterday to 21.

Unless you drained and refilled 40% of your pool, it didn't happen -- what you've encountered is just typical bogus poolstore test results. We've seen it a thousand times here!

What you have to understand is that pool stores have NO incentive to provide accurate testing, since truly accurate and reliable testing will greatly reduce their chemical sales. Not all pool stores understand this; not all pool stores *deliberately* provide bad test results. But, almost all pool stores DO provide BAD test results! And no pool stores will work hard at doing things -- like providing accurate reliable tests -- that will drastically cut their sales.

1. Get a local OTO/phenol red test kit (yellow/red drops). Make your pH stays between 7.2 and 7.8. Make sure your chlorine stays above 2.0.

2. If you've recently had metal stains, run your pump 24/7 and use polyquat (www.poolsolutions.com/polyquat.html) to help filter and to prevent algae while your chlorine is low.

3. Order a K2006 test kit (link below) .

4. Again, if you've had metal stains, do NOT shock your pool -- doing so is likely to put the metals BACK on your pool walls. Please understand, almost all 'metal remover' products ONLY remove the stains from your walls; they do NOT remove the metal from your pool water.

5. Adjust your return eyeballs, so that they are not aimed at anything that can stain.

6. Make sure your filter is working well.

7. Putting a chlorine tab in the skimmer, will help drop the metals out of the water . . . and onto your filter, instead of onto the pool walls. Using polyquat will also help filter, and will help prevent algae while your chlorine is low.

[lizbyrne2000]

After I removed the iron stains I used a product to remove the iron from the water. I keep chlorine tablets in the skimmer. There are no stains in the pool and the water looks clear and blue. I just can never get a chlorine reading. None of the pool stores around here have the 2006 water tester so I ordered one. I have been checking the PH and Chlorine with a OTO tester. Yesterday I took water samples to 3 different stores and got 3 different results.
1st one said my CYA was 21 a drop from 38 the previous day, they use some machine to test they also said my iron was 0 and chlorine 0 PH 72.

2nd said my CYA was 30 - 50 , Iron .15 & PH 7.8 they used test strips (Which I hate) Chlorine 0

3rd my CYA was 10, Iron 0 & PH 7.2 Chlorine 0 They were the only one's that tested with chemicals.

[ Admin: added image showing these results as a table. ]
https://lh3.googleusercontent.com/-7atV7jdl6TE/UcOMRHIjOsI/AAAAAAAAFmU/kX5eQX7iwPk/s365/test-results-thread-20362.jpg

I added 6 lbs of stablizer 4 lbs of shock ran filter 24 hrs (which I have been doing) about 1:00 PM tested the next morning chlorine was high by 4:00PM it was gone. The week before I added 4 lbs of stablizer. My pool is 30,000 gallons. HELP

[Watermom]

Well whatever your CYA was before may be a mystery until your K-2006 kit arrives but the 10 lbs. that you have added should have added about 45ppm. So, I guess the moral of that story is that you don't need any more stabilizer.

Have you followed Ben's advice above?

[PoolDoc]

Great example of why we don't trust pool store testing, by the way. (I couldn't resist posting a table of the results you reported!)

[lizbyrne2000]

I did buy a little kit until my big one comes, my CYA is now 50. I added something called Questout ? to remove all medals from the water. The pool looks great no algea it's clear and blue just NO CHLORINE LEVEL Free & Total CL is 0.

[lizbyrne2000]

I did buy a little kit until my big one comes, my CYA is now 50. I added something called Questout ? to remove all medals from the water. The pool looks great no algea it's clear and blue just NO CHLORINE LEVEL Free & Total CL is 0.

I just want to know what eats or kills chlorine besides the sun?????????

[stma]

Ben/ Lisa:: 5 days ago (along with the previous 4-5 weeks) my CYA level was an "uncomfortable" 65... Just took the test again (with the 2006) and the levels are -ZERO- (( Within those past 4-5 days, I've dosed PolyQuat and started the Ascorbic treatment )) Im sure you recognize my user name and know what I've been going through the past few months..... Something ate that CYA in the past 5 days.... I thought it may be the reagent itself, but it came from the same bottle that I tested with last week....
((So much for enjoyng the pool WaterMom :) ))