no chlorine

Chlorinating, maintaining the right chlorine levels,
chlorine problems. Dichlor, trichlor, cal hypo, bleach,
granules, chlorine pucks and chlorine sticks.

Postby mjcox » Mon 14 May, 2007 16:19

Just curious if any of the people on this thread with the no chlorine in the pool had their problem fixed. If so, what fixed it? I have been running my chlorinator 24/7 and although it says it is generating I am showing zero free chlorine and zero total chlorine. The pool is crystal clear so I cannot figure it out. Someone please help.


swg, but no chlorine

Postby desoto » Fri 25 May, 2007 13:42

I just resolved the same problem with my pool. As a stop-gap measure, I added a gallon of liquid chlorine to my pool. I tested the water with test strips to measure the CYA, and had the water tested at the local pool store . Both measurements showed low CYA. Added the required stabilizer, and a week later, my pool is fine, and the generator is producing again.
If you have a chlorine generator (also known as chlorinator or SWG), and are registering no chlorine, test your pool water for cyanuric acid (CYA). Have the water checked at the pool store, too. If CYA is below (or above) that recommended by the manufacturer of your chlorinator (mine is 60 to 80 ppm), the generator will not produce any chlorine.
Read your owner's manual troubleshooting section for the chlorinator.
If you need to add CYA (also known as conditioner or stabilizer), add it, but remember that it takes a few days for the new CYA to register on a test. Don't add it unless required, because too much will require partial draining of your the pool.
Also, test your salt level. Too little salt (or too much) has the same effect on your chlorinator.
It's important to check your generator for a buildup of mineral deposits that prevent the water from contacting the plates, which prevents the production of chlorine. Cleaning the plates might be in order.
Lastly, have your chlorinator tested at the local pool supply store if none of the above apply.

no clorine

Postby geo » Thu 07 Jun, 2007 20:56

my neighbor had this problem last year anr the local pool store found high levels of nitrogen in the pool, sounds weird the test takes 24 hours to run the only way I see nitrogen going in the pool is from lawn fertilizer. The guy at the local pool place said the nitro level was so high he had to lower the level by half and had to refill the pool now I am having the same problem with no clorine reading so mine is going to be tested tomorrow
Frustrated in Portland


Postby Frustrated in Portland » Fri 08 Jun, 2007 13:03

We were told by our pool maintainance company that we have a chlorine lock and the pool tested high ammonia (3 times normal). Long story short: This is the 4th time between last year and this summer that we've had to drain the pool down and refill and I'm sick of it. We don't know what the source of the ammonia is - don't fertilize, no huge crowds of people, pool is 12 years old and never had a problem until last summer.
Oh, by the way, the drain/refill last week only took the level down to 2 so we may have to do it again. Very expensive and in the meantime, nobody is swimming! Anyone have any experience in this?
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Re: Ammonia

Postby Backglass » Fri 08 Jun, 2007 13:31

Frustrated in Portland wrote:Anyone have any experience in this?
Chlorine lock is caused by high levels of CYA (stabilizer). After you get the levels down, switch to liquid chlorine. If you go right back to pucks and dry shock, you will eventually be back in the same (locked) boat again.

The ammonia is coming from <DRUMROLL> Your kids! Perspiration and Urine are mostly ammonia but because of the chlorine lock, they couldn't be removed and thus built up.

Chlorine (when free & available) oxidizes Ammonia and Nitrogen. Fix the chlorine and you fix the ammonia.

For those of you with -zero- chlorine, your CYA might be too low...or even zero. On a sunny day the sun can remove all of the chlorine from your pool in one of two hours without some CYA. It's a double edged sword. You need some...but not too much!
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Postby Dandle » Fri 15 Jun, 2007 16:28

Have just found this site after having a problem with my pool going cloudy due to not having enough chlorine in it. After adding some chlorine and it not registering I added some shock granuals which didnt register so I was told it was probably in chlorine lock. I then bought some chlorine liquid to shock it again which didnt work. I was at the end of my tether when I found this site and saw the post on too much chlorine causing a bleaching affect on the test pills. I diluted the water down by 5 times in a jug and the chlorine registered. I have now added way to much by the looks of it so will let it burn off now. Just wanted to say thanks to everyone in this post, I have learnt alot.

no free chlorine, low total chlorine

Postby spike » Fri 22 Jun, 2007 21:46

we've had difficulties maining the chlorine levels in our 22,000 gallon in ground pool. teated for phosates last fall while winterizing the pool, 1000 points before teating. opened the pool 3 weeks ago still having issues with the cholrine levels, free and total. tested for phosphates levels at 500 points. treated again still low chlorine levels. tested for phospates today, 2500 points. CYA 85, ph 7.0, alkalinity 180. using an auto chlorine dispenser. all test at conducted by a local pool store which in my view has done well in helping with pool water issues. values are obtained by sampling the pool water into a test cylinder and read via device. phosphates are tested by a dip stick. looking for direction.
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Postby chem geek » Fri 22 Jun, 2007 22:35

First of all, you should get your own quality test kit, the Taylor K-2006 (from here or here or the even better equivalent kit here), and do the tests yourself. Second, unless you consistently maintained an absolute minimum Free Chlorine (FC) level of 5 ppm FC (6 ppm FC if the pH were 7.5), then you are likely fighting a nascent algae bloom that is consuming your chlorine. A CYA level of 85 is high and requires a higher FC to keep away algae. The normal target (at a pH of 7.5 and CYA of 85) is an FC level of 9.5 ppm. Did your pool store tell you about that?

To shock algae at that high CYA level requires a very high level of chlorine. So high that it might be better to do a partial drain/refill (or continuous dilution) of your pool to get the CYA level down to something more reasonable in the 30-50 ppm range. With 40 ppm CYA, for example, the FC target is only 4.5 ppm with an absolute minimum of 3.0 ppm that is much easier to manage and if you ever do need to shock, you only need to use 16 ppm FC to do so. The rough rule is that at a pH of 7.5, the FC needs to be a minimum of 7.3% of the CYA level, the normal target FC is around 11.5% of the CYA level, and the shock level (for green algae) of FC is around 40% of the CYA level.

I'll bet you are using Trichlor tablets/pucks as your source of chlorine (you said you had an auto chlorine dispenser). For every 1 ppm FC you add with Trichlor, you are also adding 0.6 ppm CYA. I suspect you might have a cartridge or DE filter that doesn't get backwashed. With a sand filter and regular backwashing, you usually get more dilution, but with your larger 22,000 gallon pool perhaps that doesn't help anyway.

I'll bet the pool store didn't tell you anything about Trichlor adding to CYA levels, did they? Or if they did, then they probably said that the CYA level doesn't matter, at least not until it's 100. And if you look on multiple pool forums you will see how treating for phosphates is the latest rage -- and expensive to boot. It's not really the pool store's fault since most are just following what the manufacturers are telling them.

After you reach a certain CYA level in your pool, say 40 ppm, then you need to switch to another source of chlorine that does not have CYA in it such as bleach or chlorinating liquid. Even Cal-Hypo would be better, though that increases Calcium Hardness (CH). Every 1 ppm FC from Cal-Hypo also results in an increase of 0.7 ppm in CH, but that's far less of an increase in percentage terms (with a CH of around 300) than with CYA. Note that you CANNOT use Cal-Hypo in a dispenser that was used with Trichlor EVER (the two are completely incompatible and can cause a fire or explosion -- in the pool water they are fine, but cannot come in contact with each other in concentrated form).

The downside with these other forms of chlorine is that they need to be added every day unless you have a pool cover in which case you can add chlorine 2-3 times per week.

Your other option, after clearing your pool of nascent algae, is to use a weekly dose of PolyQuat 60 algaecide. You could then use Trichlor, plus the pH Up and/or Alkalinity Up products that are also required (since Trichlor is so acidic) and not worry as much about the CYA, at least for a while until it gets well over 100 ppm. Another option is to add 50 ppm Borates (from 20 Mule Team Borax plus acid) as an algaecide, though PolyQuat 60 is more effective (and more expensive since you add it weekly).

By the way, is your in-ground pool vinyl or plaster/gunite? If the latter, then you should also check your Calcium Hardness. A pH below 7.0 is damaging to metal in equipment so generally you want to avoid getting that low, at least for an extended period of time. 7.5 is a normal target pH. If you use a "pH Up" product, that increases both pH and TA. If you use 20 Mule Team Borax from the grocery store, that raises mostly pH and only half as much for TA (same with lye which is another option for raising pH). If you do end up switching away from Trichlor as your chlorine source, then you'll want to lower your TA level to reduce rising pH, but that's down the road.


Low FC level

Postby spike » Sun 24 Jun, 2007 11:04

Thank you. I do have a Taylor 2005 kit and use only Taylor reagents. The CYA as test by the pool store is correct. I will lower the CYA level by dilution. I struggled with this same issue all last year. It came to a head when the ran out of chlorine in the dispenser while away and came home to a "can't see the bottom cloudy pool". Super chlorination took care of the problem.

Yes we are using Trichlor pucks on the dispenser. We also do have a DE filter system which has beed recharged roughly 3 times sinces we opened the pool a month. This is common since the pool did have green algae growth and was dirty from the winter when opened. The recent recharge of the filter occured about two weeks ago. I expect to stick Trichlor as an oixidizer.

To clear the algae, shock or allow the chlorine to dispense of the it?

Yes it is a vinyl lined pool and I will correct the ph. Thank you for the note.
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Postby Buggsw » Sun 24 Jun, 2007 12:53

Chlorine is used to shock the pool. You get the chlorine up to shock level by adding enough chlorine.

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