Low chlorine reading

[sabres07]

Just openned my inground vinyl liner pool, 18K gallons. I shocked with 5 lbs of powder shock the first day, got no reading, so over the last week I have added another 12 pounds. This was done as I was raising ph level to 7.4. Still no chlorine reading on test strip. Am I going to have to super shock my pool because the chlorine demand is very high now?

[PoolDoc]

Begin adding 6 gallon doses of PLAIN 6% sodium hypochlorite in the late evening; test your chlorine levels with OTO (yellow drops) the following AM. If you find that you do NOT have a STRONG yellow test result, repeat the dose that evening.

There are several reasons for a very high chlorine demand, but by far the most common (this year, at least) is high stabilizer levels in the fall bio-degraded bacterially to ammonia in the spring. The levels of ammonia can be VERY high, and can require enormous doses of chlorine to resolve.

You should also use borax to maintain the pH in the higher range (7.6 - 7.8) while you're cleaning up this mess: if it is ammonia, the intermediate products that form as you break down the ammonia are much less noxious at higher pH levels.

And. . . you should get a Taylor K-2006 test kit (see the test kit info page in my signature) so we can find out what's REALLY happening.

[aylad]

sabres,

You have two posts going with basically the same question. I had replied to your other one before I saw this one. So I'm going to lock down the other one so that all of the responses will end up in one place.

When you post a question, please be a little patient with us and you will eventually get responses. When you double-post questions it clutters up the forum worse than it is already and creates quite a bit of confusion, making it hard for us to help you.

Thanks

Janet

[sabres07]

Janet,

I posted in two different locations only because I was unfamiliar with this forum. My post did not show up immediately like in other forums I belong to, so I thought that the first post unlocked your ability to post regularly. My mistake and I am sorry.

Update today: I took my sample into my pool store and they said all my numbers were good except for FC, which was zero. They said my ph was 7.7, too. I spoke to another friend who went through a similar problem a few years ago where he had to super cholrinate with 40 gallons of chlorine to break through. He mentioned another pool store that would be able to calculate how much chlorine I would need to use. I went there and they tested my water and told me that my ph was very high, 8.8. I don't know why the other store was different, but I bought my own test kit and am going to do my own testing from now on. With my test kit, my FC looks like .5, just barely there, which matches what the second store told me.

My pool is cloudy (milky white, probably from the soda ash I used when store #1 kept telling me my ph was low, eeven though my test strips were telling me it was good), so I added stuff to lower ph to the high 7 range and am preparing to super chlorinate tonight. Store #2 said they would get back to me about how much chlorine to use, they were too busy to calculate at the time I was there.

Any idea how much bleach to use to super chlorinate?? From my understanding, if you don't use enough the first time you are just wasting your money. Is that correct?

[PoolDoc]

Any idea how much bleach to use to super chlorinate?? From my understanding, if you don't use enough the first time you are just wasting your money. Is that correct?

It's never exactly true. It is true with algae, that if you aren't getting ahead, you are getting behind. But, with white cloudy water, algae is not your immediate problem. (Sweep the pool to make sure you don't have algae piles on the bottom!)

You need to add pool info to your signature: type, dimensions, gallons as you've been told (usually inflated), pump/filter make/model, etc. There's a link in my signature block. I just put what I could find, there.

BUT . . . if you have ZERO CYA, a high chlorine demand, and had a signficant CYA level last fall, there's a fair chance you have ammonia in the pool.

In your case, with 18K gallons, a gallon of PLAIN 6% household bleach should add about 3 ppm of chlorine to your pool. You don't want to go TOO high, all at once and fade your liner. (It may happen anyhow: liner color stability is unpredictable). So add 4 - 5 gallons of bleach each evening. Test in the AM with an OTO (yellow drops) kit. If the chlorine is gone, add 2 gallons.

Repeat this dose until you hold a high chlorine level overnight.

[sabres07]

Yes, I bought a nice brush today and vigorously brushed the side walls. I then vacuumed the pool as best I could and ran it to waste instead of filter.

I have read many other threads here regarding algae problems, and am confused. Your recommendation is to only add 4-54 gallons of bleach tonight and re-test in the morning....if gone add 2 gallons right away in the AM? Repeat this process until chlorine holds all night??

[PoolDoc]

If your pool is green -- you have an algae problem.

If your pool is cloudy white and doesn't not turn green when you brush, and you can't hold chlorine overnight . . . you have a DIFFERENT problem.

Either way, getting chlorine to hold overnight is a key first step. But, I want to avoid massive doses that might temporarily be high enough to bleach your liner. So, until you have a good kit and have given us test results, I'd recommend sticking with the doses I suggested.

[sabres07]

OK, so I got a test kit today and did my own tests, here are the results:

ph 7.8 (I added acid today to lower)
FC .6
CC 1.0
TA 210


After reading numerous posts on this board, I suspect my cloudy water problem stems from high TA and the soda ash that I added because pool store #1 told me my ph was low, even though my test strips told me it was OK. I also understand that TA is diufficult to lower. Pool store #2 suggested removing some water and replacing....then repeat again.

After scrubbing the sides and floor of the pool, it still stays a milky white color, and I can only see about 12-18 inches down. Earlier in the week prior to adding soda ash, I could see the bottom of the shallow end but not the deep end. I just discovered after reading here that soda ash also raises alkalinity, so I created my own problem it seems.

How do I proceed from here??? Should I remove water, add water and shock with bleach? That is the way I am leaning now. Thanks in advance for any help!!!!

[PoolDoc]

1. Get a kit that measures calcium hardness and stabilizer! Tell us what you have.

2. Use muriatic acid (read the page linked in my signature!!) and lower the pH, a little at a time, to just above 7.0 . . . and KEEP it there. It will keep trying to rise.

[sabres07]

I forgot to add those.

Calcium hardness 250
CA 30


I am getting a better tester kit because I can see that I can trust my numbers more than the pool stores.

By the way, store #2 called back and suggested hitting my pool with 19 gallons of chlorine to super chlorinate but I am going to go with 6 gallons as suggested here and retest in the morning