How to Cure CHLORINE LOCK and CHLORINE DEMAND

Swim University makes pool and hot tub care easy for millions of homeowners. Each year, we continue to help more people with water chemistry, cleaning, and troubleshooting. We know taking care of a swimming pool or spa can be difficult. And it’s hard to find a trusted source of information. This is the reason we created Swim University.

If you’ve just added chlorine or shock to your pool, and your tests are showing low chlorine levels -- or no chlorine at all -- you’ve got a Chlorine Demand problem on your hands. And Chlorine Demand is a completely different issue than Chlorine Lock. Luckily, there are some simple ways to get your chlorine levels back to normal.

⏰ Timestamps:
00:00 - Introduction to How To Cure Chlorine Lock and Chlorine Demand
00:38 - Chlorine Demand vs. Chlorine Lock
01:33 - What Is Chlorine Demand?
02:29 - How To Tell If You Have A Chlorine Demand Problem
02:52 - How To Cure Chlorine Demand
03:14 - How To Prevent Chlorine Demand

[DonPatch]

You literally just gave me the answer to all problems I’ve been running into! Thank you!!!

[frank]

Wow. What an amazing video. I am a new pool owner. I understand the science behind pool chemicals. This is the most comprehensive video and makes complete sense to what I am experiencing with my own pool! Best video!! Hands down!!

[garethjones]

As Mike L said, this is happening to me right now and this video couldn’t come at a better time, thank you so much. The pool is getting a shocking tonight lol 😂

[nickl]

Thanks for making this easy to understand and actually what to do. So many just talk about, "it could be this, or it could be that".

[seanstrickland]

I had the pool tested after the pool guy Chlorine levels 00.14 man does nothing besides collect a check.

[brianandmelsikorski]

Thanks. Just discovered the same issue. We’d put chlorine in and in a few hours, it would be gone.

[mandosanchez]

Wow I’m doing this in the morning I had 0 cl reading all day and I know it’s cl in there Thank you

[mikel]

oh man thank you so much for this video and it couldn't have come at a better time...i'm having this EXACT issue right now and its getting frustrating. It all adds up though all of the reasons you said. Really appreciate you sir keep up the good work very glad I subscribed to your email list.

[erinanderson]

Your videos are always helpful. The videos have kept my pool and water clean and clear for 3 yrs now :)

[jrhumphreys]

We where adding tons of chlorine. Not until we tested and found high phosphate levels (we live near a bunch of farms) and took care of that issues no amount of shocking and additional chlorine could get our chlorine level to increase.

[sonoflavadome]

This video is nicely done, however it does not address the issue of having high total chlorine, and very low/no free chlorine. This is what the chlorine lock reference is about, or at least when I have heard it used. The video ambiguously refers to 'chlorine levels' throughout, and does not differentiate btwn the two (really there are three chlorine levels if you throw is combined).

[gardengrovemike]

Will try this tonight... All my levels are in range except the chlorine level, it stays at .5 or less and I added about 3/4ths of a gallon of liqud chlorine and still low reading.. I'll super shock tonight and hopefully this works!

[randyericasmith]

LOVE your videos - they are incredibly helpful!

[douglasjackson]

Love this information, you guys are so helpful.

[iProDan]

I had this last year. Nightmare. I had three companies all tell me different things. I researched YouTube. My ONLY fix was to balance my ALK and PH to perfection, then BINGO, it unlocked. Very weird and frustrating

[alkare]

Opening a late covered pool & pool was still cloudy after 2 weeks. Pool store told me I have chlorine lock. Test kit was bright yellow. They sold me non-chlorine shock, & it finally started to clear up. 3rd week in opening a late covered pool. Who knows?? But I’m finally seeing the light(bottom)

[Jasheon]

Yeah i had a pool a few years ago with insane chlorine much debris and vegetation around the pool, it was a money pit.

[lovelylyfe]

I put 2lba of shock . Let it sit over night. And it's all clear but cloudy. I put some ph in it. And a bottle of I bought XtraBlue Algaecide 40 oz. Algae Prevention and Algaecide and Xtra shock. I put it in the morning and I let it sit for 2 hours and then the ph

[trevorspottiswood]

Thank you for the very helpful information.

[ashfordjoseph]

Lol it’s isn’t a myth if you said to make sure when you triple shock it to have your cya levels at 30-50 and not high as hell