Can't maintain chlorine levels

Jump to latest Follow Reply
J

joelalbert

0
Jun 4, 2016
12
Bala Cynwyd, Pennsylvania
For the first time ever my pool, since I opened it 5/15, is not maintaining chlorine. My stabilizer is a bit high but that doesn't seem to be the problem.

I add chlorine via a chlorinator, by sprinkling granules around the pool and by putting tabs in the skimmers.

Nevertheless, the chlorine readings go down almost immediately after application.
 
Welcome to TFP. Good to have you aboard.

The format for communicating test results is described in "read before you post" (link in my signature)

Free tests from pool stores are seldom accurate, so you're going to want to have a Taylor K2006 or TFTestKits TF-100 test kit if you don't already have one. You will save back the cost quickly by using TFP methods to maintain your pool. If you don't already have one of these, post whatever results you can, but be sure to indicate the source of the tests.
 
If it were me, I would stop using granular and pucks at this stage. Your CYA at 40 PPM (if the pool store is correct) is fine, so no need to add any more until the problem is diagnosed. I would order a TF100 test kit here TFTestkits.net. This kit, or a Taylor K2006, will give you the FAS-DPD chlorine test you need to take charge of your pool chemistry. I have no affiliation with TF test kits. You won't regret adding the XL option and a speed stirrer.

In the meantime, I'd add a full 121 oz or 128 oz jug of 8.25% bleach (not scented or splashless) which will provide 4 PPM FC. Zero FC is not safe for swimming and algae is likely getting started.

And then half to 3/4 of a jug each day until the test kit arrives. (2 to 3 PPM per day)

Are you testing chlorine yourself now? If so, what test kit do you have? You may be able to use the 5 PPM color match to judge whether or not you're close to 4 PPM and let us know how long the FC is holding up.
 
Joel,

I deleted your water analysis sheet because it contained personally identifiable information, a bad thing to readily post on the web and TFP discourages it.

For the benefit of others, it is a Leslie's printout with the following results
FC 0
CC 0
pH 7.6
TA 120
CYA 40

Pool store analysis is notoriously incorrect. In this case if you consistantly chlorinate with tabs and powdered shock I am surprised with the he low CYA.

As others will point out, taking control of your pool and self testing with a reliable test kit is the first step. The fact that the CYA is above "0" and you can't keep chlorine in the water tells me something is growing.
 
I ordered the test kit recommended above. Thank you

- - - Updated - - -

I ordered the test kit. Thank you.

I will try the bleach and report back. Do I apply this directly or mix with water and then distribute?

I am testing chlorine now myself with test strips. When I add chlorine I test and see high levels of chlorine but it seems to go down again very quickly (under an hour).
 
Glad to hear you ordered the test kit. We'll have to wait for the test kit to get started, but there's only a few possibilities. Better experts will chime in wherever I'm wrong.

1. There's an algae bloom underway, and the bleach was consumed neutralizing it.
2. It's less common, but possible you have CYA-eating bacteria, that convert CYA to ammonia. The ammonia will consume the free chlorine very quickly. The puzzle is that CYA is usually zero if this condition exists, but maybe Leslie's result was off (this is the other thing we need the proper kit for)
3. If CYA is zero, and your tests were done in full sun, FC would drop from 4 to 2 in about a half-hour, and then from 2 to 1 in the next half hour, so you should have detected some on the test-strip. It sounds like the test strips are fresh because you did detect FC after adding the bleach.

We've yet to hear what your water looks like. It could be clear under these conditions, but more likely a bit cloudy and whitish, bluish, or green. Could you describe it?

This may not prove helpful, but please pour another gallon in after the sun is off the pool with your pump running and do a test 10 minutes after adding the bleach, and then again 10 minutes after that. If you have lots of strips, another at 30 minutes and/or 1 hour might be helpful. When you get your kit, you won't need the strips anymore.

When you get a chance, please add your pool finish, pump HP, and filter type to your signature. Not relevant yet, but it will be later. Thanks.
 

Enjoying this content?

Support TFP with a donation.

Give Support
Let us know if and when you detect any "motel pool smell" - the smell comes from chloramines and it might help us understand the situation better. Chlorine itself is odorless, so the smell most people call "pool smell" or "chlorine smell" is a helpful indicator.
 
Thank you everyone for your input.

My water is crystal clear. My finish is plaster, I have a whisper flow pump (need to check horsepower) and a separate pump for the Polaris. My filter uses DE and I back-washed this past Saturday just to see if that, and adding some fresh water, would help. It did not.

I detect no unusual smell.
 
Thanks for describing the pool and updating your signature. A gallon jug of 8.25% bleach will add 4 PPM FC each day until the test kit arrives. With reliable numbers you'll be able to get started on solving the chlorine mystery. In the meantime, if you want to, take a look at a few links here that should be helpful later on. A lot will be old hat to you but they helped me get the TFPC methods and lingo.

Pool School - ABCs of Pool Water Chemistry
Pool School - Recommended Levels
Pool School - Chlorine / CYA Chart
These three cover TFPC water chemistry methods really well and are quite concise and well written

As for taking charge of your own reliable testing, this link has videos of a few of the tests
https://www.youtube.com/user/tf100testkit?feature=results_main

And this one has the full written instructions and some tips and tricks as well
Pool School - Extended Test Kit Directions
 
Phosphates is a scare tactic to sell you products you really don't need.

When you get your test kit I think an OCLT will prove something is growing in the water. Read up on the SLAM and get ready. With a little luck a clear water SLAM will go quickly. I had to do one last year and it was only 4 days.
 
Taylor K-2006 arrived. I have one question: For the Free and Combined Chlorine Test its says
"NOTE: For 1 drop=0.2 ppm, use 25 mL sample. For 1 drop = 0.5 ppm, use 10 mL sample".

Any idea which "drop" I should use?

Also, my chlorine is holding. I occasionally smell that "motel pool" smell but is it possible my problem is resolved?
 
For everything we do, the 10 ml sample for free chlorine (FC) is the one to use. If you use 7 drops to cause the sample to change back from pink to clear, it's 7 times 0.5 = 3.5 PPM. Post all your numbers when you've finished the testing. Someone will be here to interpret and let you know if anything is needed.

The best way to find out if there's an issue is to do the "OCLT" Pool School - Perform the Overnight FC Loss Test (OCLT)
 

Enjoying this content?

Support TFP with a donation.

Give Support
You must log in or register to reply here.
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.
Top Bottom
Back
Jump to latest Follow Reply