Free chlorine not detected with test strips

[mars23]

Hi everyone,
I recently bought a above ground pool 10 x 30 I looked into how to maintain it so I put a 1 inch chlorine tablet, 1/3 of clear balance tablet And tested the next day to check the levels, the strip detected everything (alkalinity, cyanurid acid, ph) but the free chlorine remains at 0 despite the tablet still dissolving in the dispenser.
I don’t know if the strips are bad or the chlorine tablets are bad? I used the brand HTH
What could be the problem please?

thank you

 

[JohnT]

Welcome to TFP!

Tablets are slow an problematic. Test strips are also problematic.

Your pool is likely 6300 to 8300 gallons, depending on the water depth. Add two quarts of laundry bleach trickled around the edge with the pump running. Wait 15 minutes and test.

You have the slow dissolving tablet working against you, and the rapid breakdown of chlorine from sunlight using up your chlorine faster than a little tablet can dissolve.

Ditch the tablets, and maintain with bleach. You'll need stabilizer or Cyanuric Acid (CYA) to keep the sun from eating your chlorine. It's very much a Goldilocks thing though. Too much is bad, and too little is bad. You want it just right.

Take a look at ABC's of Pool Water Chemistry and What Are My Ideal Pool Levels? to get started

 

[ajw22]

Welcome to TFP.

We recommend the Taylor K-2006C or TFT Test Kits be used since test strips are know to be inaccurate.

You may not have enough CYA in the pool to protect the chlorine from being consumed by the suns UV.

I suggest you read...

Pool Care Basics Archives

Your one-stop shop for all things TFP to include: ABCs of Water Chemistry, Recommended Chemicals/Levels, Test Kits, Troubleshooting, and much more!

www.troublefreepool.com

 

[mars23]

Welcome to TFP!

Tablets are slow an problematic. Test strips are also problematic.

Your pool is likely 6300 to 8300 gallons, depending on the water depth. Add two quarts of laundry bleach trickled around the edge with the pump running. Wait 15 minutes and test.

You have the slow dissolving tablet working against you, and the rapid breakdown of chlorine from sunlight using up your chlorine faster than a little tablet can dissolve.

Ditch the tablets, and maintain with bleach. You'll need stabilizer or Cyanuric Acid (CYA) to keep the sun from eating your chlorine. It's very much a Goldilocks thing though. Too much is bad, and too little is bad. You want it just right.

Take a look at ABC's of Pool Water Chemistry and What Are My Ideal Pool Levels? to get started

Thank you so much for your reply. I will definitely try with bleach then, my pool is around 1100 gallons so how much bleach should i pour inside? and how long should i wait before jumping in the pool?
As for the strips, I tried dipping two differents brands to see if they would react to the bleach and here’s the results on the picture attached.
Looks like the left one reacted a lot more than the right one regarding the free chlorine.

 

[JohnT]

Thank you so much for your reply. I will definitely try with bleach then, my pool is around 1100 gallons so how much bleach should i pour inside? and how long should i wait before jumping in the pool?
As for the strips, I tried dipping two differents brands to see if they would react to the bleach and here’s the results on the picture attached.
Looks like the left one reacted a lot more than the right one regarding the free chlorine.

1100 gallons? You need to clarify dimensions. 10x30 would imply a 10’x30’ oval. Do you mean 10’ round by 30” deep? If that’s correct, start with a pint.

 

[mars23]

yes that’s correct, thanks a lot!

 

[Bperry]

yes that’s correct, thanks a lot!

Just use plain plain bleach. No clorox, or anything with perfumes, fabric softeners, etc. Best option is “chlorinating liquid” from Walmart, Home Depot, etc.

 

[mars23]

thank you! i will check it out, how long should i wait before jumping into the pool? and how often should i do this treatment?

 

[ajw22]

thank you! i will check it out, how long should i wait before jumping into the pool? and how often should i do this treatment?

What treatment are you asking about?

 

[mars23]

Adding bleach to the pool

 

[ajw22]

Adding bleach to the pool

Wait 15 minutes after adding chlorine.

 

[mknauss]

With your small pool volume, I suggest you review Guide for Seasonal/Temporary Pools and manage your pool water chemistry using that guide. You will need a simple drop based test kit you can get at Walmart or Home Depot, etc. If the pool becomes cloudy, you will drain it and start over.

 

[mars23]

I added bleach to it and waited 15 min now the free chlorine shows at the level it should be on the test which didn’t happen before. Thank you everyone for your help!

 

[ajw22]

I added bleach to it and waited 15 min now the free chlorine shows at the level it should be on the test which didn’t happen before. Thank you everyone for your help!

That says algae or the suns UV are consuming the chlorine.