My Total Chlorine Is 3, But No Free Chlorine In The Pool…


I have a 18 foot round pool and I seem to be having chlorine demand I test the water and I get no chlorine reading I took a sample to a local pool store and they said my total chlorine was at around a 3 and my free was at 0 my ph and alkalinity reading are fine my cya is a little high at 80 but it read that last year and didn’t have this problem I added powder chlorine and then tried liquid and even oxidizing powder and nothing seems to break it I need help cause no one can seem to solve this problem for me it is weird my water is clear and right now my pool has a powerful bleach smell cause of the chlorine I added but no free chlorine reading so any help you can give me I really appreciate it a lot maybe I need to add a lot more shock then I added? The most I added at a time was 3 lbs of powder then I tried 3 gallons of the liquid form.




If you have chlorine locked – it would cause the readings you are getting and for the smell to be present. The used chlorine has locked all available chlorine and is stuck together with contaminants. You need to super chlorinate to break the bonds – though if you have a high TDS Total Dissolved Solids reading that could contribute as well.

I would add 1 case of liquid chlorine from a pool supply store – I’d be afraid anything from a big box store wouldn’t be strong enough.

Also have your TDS checked – if they are too high you will need to drain and refill some water – it doesn’t happen a lot but if your main sanitizer is stabilized chlorine tablets and your water can’t absorb any more chemicals it will cause the bind as well. With a stabilizer level at 80 you are on the verge of high – any higher and definitely switch out some water…

In the meantime try the shock – in this case as well a non chlorine shock/oxidizer won’t be strong enough to break those bonds and free up chlorine…

Good luck!



I have a lot of the calcium powder shock and trichloride shock would one of them do the trick? If so how much would I have to add to the pool? If not what kind of liquid chlorine would I have to add and how many gallons? I added 3 gallons previously and didn’t do a thing the powder shock I have comes in 1 lb bags



I’d suggest the 10-14% liquid chlorine x4 gallons. Some states don’t allow chlorine transport – not sure where you are located?

Calcium hypochlorite dissolved in a bucket would do the trick. I’d do at least 4 of them – if you aren’t getting any results, you need to do more. The hesitation with cal-hypo is if it settles it will bleach the bottom of the pool.

You don’t want stabilized chlorine so read the packages – if it says stabilized it’s not going to be an effective shock treatment for what you need.

It also must have chlorine – any oxidizer without chlorine won’t work for this.

…also avoid any products purchased from intheswim or similar discount online sources.


Also: if you have a dog that swims, a dog is like 50 bathers in the pool – so at least double the treatment suggested.