How do you raise free chlorine levels in a pool?

Answer 1

You need a test kit to determine free chlorine levels. To reach those levels you test the water and add chlorine until you achieve the required amount ( 1.5 to 5.0 ppm) of chlor. The first reading on the kit is available chlor. The second part of the test would determine the free chlor level. The free chlorine is what is doing the sanitizing or killing of bacteria. The first reading only tells you that you have some chlor in the water. It is probably not safe to use the pool if you do not have a sufficient amount of free chlor. k

Answer 2

Keep your pH within 7.1 to 7.8, ideally 7.4. Consider adding Potassium monopersulfate to assist your chlorine additive. Some people will disagree with this but I fought with free chlorine levels for the past 3 years. More chlorine (7 lbs of lithium hypochlorite) was added and the next day, my free chlorine level was 0!!! Chlorine evaporates and quickly forms chloroamines. No more free chlorine. Use the PMS to snatch up the amines (urine, suntan lotion, sweat, etc) leaving the chlorine free to kill bacteria. My water has never been clearer and my chlorine bill so low. I am now able to keep my floaters filled with tablets and no longer have to use the granular hypochlorite.

It looks as if your pool suffered from a mechanism called "pH bounce", whereby it's very hard to keep the pH stable so preventing the other chemicals from working properly.

Do you use stabiliser? (Sodium Isocyanurate, I think, usually added to the chlorine-compound product.)

Incidentally it's those amines that create the unpleasant "chlorine" smell and irritation, not the disinfectant - unless you very heavily overdose the pool. If not doing so already, you could also take a leaf out the commercial operators' book & insist users shower first to rinse off the worst of the lotion and biological nasties.

Answer 3

Obviously, chlorine is raised by adding it, but, if you are not testing for total chlorine, you dont know if you have a problem.

Chlorine gets "locked up" with organic compounds like bather waste, suntan lotion and anything that grows and dies like algae or leaves. This is called "combined chlorine". You can have quite a bit of chlorine in the water, but it's all locked up with organics and unusable as sanitizer.

So the question is, are you getting enough chlorine into the water at a sufficient rate to keep up with the loss from usage and sunlite, and is that chlorine free to use as sanitizer "free chlorine" or is it bound together with organics and useless?

This is where the test for total chlorine comes into play. It tells you how much chlorine period, is in the water.

A good test kit will tell you both. If you use strips, get the "Aquachek Select" type instead of the "yellow" bottle to show both types of chlorine.

If there is a sizeable difference between free and total chlorine, it indicates the presence of organics and they need to be removed. You remove organics by "shocking" or "oxidizing" the real term. This frees up the chlorine again.

Pool & Spa

"Locking" can also occur over time with an excessive accumulation of stabiliser, ironical though that may seem, if you are using stabilised compounds.

Answer 4

You'll need to shock the pool or super chlorinate it.

Shock treatment to kill off any nasties & return the Cl level to correct, then resume normal dosing & testing. NB: test & if necessary adjust the pH first.

Non-stabilised chlorine breaks down rapidly in sunlight, so if not already doing so you may consider using stabilised chlorine compounds - but don't overdo the stabiliser if added separately because that can accumulate over a long time and reduce the chlorine's effectiveness.