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

[sabres07]

CA 30
Hardness 250
ph 7.8
FC 0
TA 210

So after sundown at around 8 PM, I added 7 gallons of regular bleach. I tested after about 15 minutes and ph was WAY high but I figured it was a false read due to the bleach I just added. The FC was off the charts, my test strips went dark purple and my OTO was VERY yellow. I figured I was good for the night.

So now it's 11:40 PM and I figured I would re-test. FC is now VERY low, .6, and ph was back to 7.8. That tells me something is using up my chlorine at a CRAZY level. It went from somewhere over 10 ppm to almost nothing in a few hours. Now I think I am gonna have to go over the top with the bleach to kill whatever (amonia, bacteria or algae) is living in my pool.

Any thoughts here?

[PoolDoc]

Yep.

Lower the pH
Add chlorine each evening
Check chlorine each AM
Do not use mega-doses of chlorine

[PoolDoc]

Any thoughts here?

Not so much. What you're experiencing is pretty much standard for folks with ammonia from CYA in their pool.

Don't let yourself get impatient and
go over the top with the bleach -- you'll end up with real problems. Instead, simply hang in there with repeated moderate chlorine doses. If you like, you can close up the interval on the doses, doing one at 7pm and another at 11pm. But test with OTO before you dose. If you don't test, you'll suddenly end up with extremely high chlorine levels, and with no CYA in the pool you're liable to end up with a bleached liner.

[sabres07]

If you don't test, you'll suddenly end up with extremely high chlorine levels, and with no CYA in the pool you're liable to end up with a bleached liner.

OK, I will stay the course. I do have a 30 for CYA. Does that change your opinion on what I should do?

Thanks for all of your help so far.

[PoolDoc]

I do have a 30 for CYA. Does that change your opinion on what I should do?

No.

[sabres07]

So I tested my water this morning and my ph went from 7.8 down to 7.2 overnight. I did not add any acid or anything else to the water. What would cause the ph to drop like that????

[PoolDoc]

Did your chlorine also drop? When chlorine is used up, the end product is acidic.

[sabres07]

Yes, I dumped in 7 gallons of bleach at 8 PM and tested the water shortly after. I finally had a high chlorine reading. At 11 PM I retested and the chlorine was at 0 and ph was at 7.8 or so. This morning I tested the water, and chlorine was still 0 but ph had dropped to 7.2.

My plan is to put 7 more gallons in tonight at 7 PM, and then re-test at 11 PM to see if it held or not. If it dropped again, I will reapply 7 more gallons of bleach. I am trying to break this ammonia or bacterial trap I am in. I was just wondering about this ph drop I had and how I should handle it in the middle of this trap I am in.

At 7:30 PM I added 6 gallons of bleach, chlorine readings were very high. I have retested every half hour since then and the chlorine seems to be holding. The ph however is dropping. It is at 6.8 now at 9:45 PM. Should I address this or should I just stay the course and keep the pool in shock mode?

[PoolDoc]

If you have some borax, I'd go ahead and add a box. It's not a crisis, but you don't want to leave the pH below 7.0 indefinitely.

[sabres07]

So after testing the pool at 11:30 PM last night, I was showing a reading above 5 ppm (as high as my test allows) but it was not as yellow as when 6 gallons of bleach was added at 7:30 PM. I added another 6 gallons of bleach. At 6 AM this morning, I tested and re-added 6 more gallons of bleach. Ph seems to be spiking when chlorine is added, as expected, and settles in at 7.2 hours later. Water is still cloudy, though.

I think I have turned the corner in my battle with whatever is causing my chlorine demand. Now I need a test kit that reads higher than 5 ppm chlorine. Does the 6 way HTH kit from Walmart read that high? I can get one today, otherwise I will order one from Amazon.

[Watermom]

The 6-Way kit does not read higher than 5. Only a FAS-DPD test can. That is why we encourage people to buy the Taylor K-2006 or 2006C kit.

[sabres07]

OK, I will get that test kit ASAP. In the meantime, based on amounts of bleach I have used, my chlorine levels should be 15-20 at the least, which is where I want to be for now, right?

[PoolDoc]

Just one emendation: the 6-way does not READ higher than 5 ppm, but it does INDICATE higher levels, by a transition from dark yellow (~10 ppm) to orange (~30 ppm) to brown (> 60 ppm).

This is a VERY important difference from the DPD color match tests, which can bleach out and read 0.0 at FC levels as low as 15 ppm! Before we began pushing OTO *or* DPD-FAS kits, we used to have lots of problems with people adding more and more chlorine to their pool, think they had none, when in fact it was way too high.

[sabres07]

Yes, my test kit does go very yellow, to orange, which is where I am at right now this afternoon. I am keeping it there until tomorrow. It looks like it is holding on its own, and it is pretty sunny today.

I have added a home made aerator because my next problem is to lower TA. When this is making bubbles on my water, I am now getting some foaminess. Is that as a result of all the soda ash I added previously? Water looks very blue but still cloudy.

[Watermom]

Foaming is usually the result of cheap algaecides being added.

[PoolDoc]

Foamy pool water usually is a result of algaecide use.

[Watermom]

Looks like PoolDoc and I were posting at the same time!

(P.S. I'm glad to know that he knew the correct answer! :p;) )

[PBLsQuad450]

Maybe not ideal but your sticky on measuring Cl with a cheap kit might make things a little more accurate?

http://www.poolsolutions.com/gd/how-to-test-your-pool-without-a-good-testkit.html

[sabres07]

I am headed to the store to get some distilled water. I am really curious what my chlorine level is at. After numerous tests today, it appears as though it has remained stable (shock level). I am really curious why the water is still so cloudy. Is it possible to reach a point where there is no chlorine load anymore but the water still remains cloudy? I still believe that I added too much soda ash at the recommendation of the local pool store. I think all the excess soda ash is just in suspension? If that is the case, what should I do?

[PoolDoc]

Is it possible to reach a point where there is no chlorine load anymore but the water still remains cloudy? I still believe that I added too much soda ash at the recommendation of the local pool store. I think all the excess soda ash is just in suspension?

Nah! Soda ash is extremely soluble. And yes, pool water can be cloudy AFTER there's no longer any chlorine demand. There are at least a dozen reasons why that can be the case.

It's usually NOT worthwhile to try to figure out exactly what's going on . . . unless your purpose in having a pool is so you can do water treatment experiments! Instead, get your water right; get your filter right . . . and then wait!

[sabres07]

UPDATE: Staying with the program here. I FINALLY see some small improvement. I can actually see the bottom of my pool a little, but only in the shallow end. This improved slightly during the day into this evening to the point where I can just make out my vacuum when I am halfway down towards the deepest part of my pool. VERY slow progress, but I will take any progress at this point!!!!

[sabres07]

I am able to see my main drain, just barely. Shallow end is getting incrementally better. It seems like it is taking a long time to clear the cloudiness here. The water is very blue, just cloudy. Still holding chlorine up over 20 ppm until I get my Taylor 2006c kit. I vacuumed to waste today in case there was any organic stuff on the bottom.

My question is : should it take this long?? It's been 4 days now.

Thanks.

[PoolDoc]

In my experience, to go from spring slime to totally clear takes a week AFTER 100% of the algae is dead, and IF you have a good filter setup.

You can do it faster with floc . . . but floc is unpredictable; everything has to be done right OR you can make it worse. And, you have to vacuum it out, JUST RIGHT. I found I was never able to depend on pool staff to do it 'right'; they'd get an a hurry, and re-suspend the stuff.

So, is 4 days too long? Nah. And if your cartridge is in crappy condition, or was a low-grade aftermarket model (ie, not OEM and not Wilbur or Unicel), it may take quite a bit longer.

[sabres07]

UPDATE: My pool is almost completely clear!!!! I am amazed that the BBB system is so easy and works as advertised.

To summarize, upon pool open this spring, I was dumping tons of powdered shock into the water, and was getting 0 FC readings. The local pool store was trying to sell me all kinds of stuff. I then found this site, and was educated properly, andwas told I was fighting an amonia buildup brought on by some type of baterial break down of CYA. It took and enormous amount of chlorine (38 gallons) over three days to break the cycle. I am still waiting for my Taylor 2006c kit to arrive to do accurate testing, but based on what I see, I have success!!

Thanks so much for all of the help. Oh, and for those who are reading and following along, the most important thing to utilize is P.O.P.P., and patience is the most important one!

[aylad]

Congratulations!! Now go enjoy your pool! :cool:

[Watermom]

Moblaine --- I moved your post into its own thread. You can find it here:
http://www.poolforum.com/pf2/showthread.php?16283-Moblaine-s-pool