Where is my chlorine going?

mommytotwins

Well-known member
Mar 30, 2015
47
NC
We opened the pool early this year because of Covid and we were home and had time. We’ve definitely had a spring here in NC with lower temperatures and rainy weather. I have added liquid chlorine multiple times and it never goes up!
Here are my readings from this morning:
pH <7
TA 40
FC & CC can’t even get a smidge of pink
CH 100
CYA the water is still crystal clear at -30

what is my first step? Btw, liquid chlorine is impossible to find locally. My water is clear as a bell!
 

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Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
It appears you have a few things to consider. Since the black dot never disappeared, you have next to no stabilizer (CYA) in the water. Before you add any stabilizer though, review both A & B below and perform as it applies (have some chlorine/bleach ready):
A) Add enough chlorine/bleach to get the FC to 10. Check it in 10 minutes. If the FC fell below 5, increase it right away back to 10 and test again in 10 minutes. Repeat as necessary. Once it holds at 5 or more, add stabilizer for a CYA goal of 30, increase the FC to "12" and begin a SLAM Process until you pass all 3 criteria.
B) If the FC held between 5-10 on the first try with no problem, then go ahead and add stabilizer for a CYA goal of 30 and balance according to the FC/CYA Chart. Use the sock-soaking method to dissolve it. You can test the CYA the next day.

- Also increase the pH and TA a bit. Since both are low, you can use some soda ash (washing soda). If you don't have that, try some Borax. If all you have right now is baking soda, that will increase the TA and may help the pH start to rise as well. Try to get the TA to about 50-70. If you had to do item A above (SLAM), then the pH only needs to make it to about 7.0-7.2. If you don't need to SLAM (item B), then let the pH climb into the mid 7s.

You'll need chlorine/regular bleach. There's just no way around that, especially if you need more for multiple 10-min tests or a SLAM. Try Walmart's Pool Essentials in the outdoor section or their Great Value laundry bleach (plan/regular). Also try Lowe's or Home Depot's pool section. Good luck!
 

mommytotwins

Well-known member
Mar 30, 2015
47
NC
It appears you have a few things to consider. Since the black dot never disappeared, you have next to no stabilizer (CYA) in the water. Before you add any stabilizer though, review both A & B below and perform as it applies (have some chlorine/bleach ready):
A) Add enough chlorine/bleach to get the FC to 10. Check it in 10 minutes. If the FC fell below 5, increase it right away back to 10 and test again in 10 minutes. Repeat as necessary. Once it holds at 5 or more, add stabilizer for a CYA goal of 30, increase the FC to "12" and begin a SLAM Process until you pass all 3 criteria.
B) If the FC held between 5-10 on the first try with no problem, then go ahead and add stabilizer for a CYA goal of 30 and balance according to the FC/CYA Chart. Use the sock-soaking method to dissolve it. You can test the CYA the next day.

- Also increase the pH and TA a bit. Since both are low, you can use some soda ash (washing soda). If you don't have that, try some Borax. If all you have right now is baking soda, that will increase the TA and may help the pH start to rise as well. Try to get the TA to about 50-70. If you had to do item A above (SLAM), then the pH only needs to make it to about 7.0-7.2. If you don't need to SLAM (item B), then let the pH climb into the mid 7s.

You'll need chlorine/regular bleach. There's just no way around that, especially if you need more for multiple 10-min tests or a SLAM. Try Walmart's Pool Essentials in the outdoor section or their Great Value laundry bleach (plan/regular). Also try Lowe's or Home Depot's pool section. Good luck!
Thanks so much for the help! Can I use Shock (I have that) or do I have to use liquid chlorine/bleach?
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Can I use Shock (I have that) or do I have to use liquid chlorine/bleach?
If you are referring to the pool store bags, they have their place at times, but this isn't the best times because you need a quick and predictable increase in FC for those tests. Also, those bags container stabilizer (or calcium) which you will add later. I wouldn't use those bags until after the pool is up & running good (chemically).
 
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Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
You can assume the stabilizer will reach the target you were aiming for. If you wish to validate, I'd do it tomorrow afternoon with good sun behind you. It should be close. While your FC didn't all below 5, it came close. Part of that may be simply because you had very little CYA to protect it today. To be safe though, I would recommend you continue to keep the FC elevated to about 10 at least through the rest of today and before bed. Take one last FC reading before bed as test #1 of an Overnight Chlorine Loss Test. Leave the pump running overnight (low is fine) and test again in the morning before the sun hits the water. Let's see if you lose more than 1 ppm of FC overnight. Even though the water may seem clear, it's best to make sure now before summer temps get here.
 
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mommytotwins

Well-known member
Mar 30, 2015
47
NC
You can assume the stabilizer will reach the target you were aiming for. If you wish to validate, I'd do it tomorrow afternoon with good sun behind you. It should be close. While your FC didn't all below 5, it came close. Part of that may be simply because you had very little CYA to protect it today. To be safe though, I would recommend you continue to keep the FC elevated to about 10 at least through the rest of today and before bed. Take one last FC reading before bed as test #1 of an Overnight Chlorine Loss Test. Leave the pump running overnight (low is fine) and test again in the morning before the sun hits the water. Let's see if you lose more than 1 ppm of FC overnight. Even though the water may seem clear, it's best to make sure now before summer temps get here.
So I think SLAM is in order? FC was at 7 last night and 4.4 this morning. ? The water is cloudy this morning. Can I say I’m super nervous about that process!!?
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Nothing to fear, TFP is here! :LOL::ROFLMAO: Simple .... verify pH is at about 7.2, check your current CYA on the FC/CYA Chart and increase the FC to that SLAM level. So if your last CYA was 30, increase the FC to 12 and keep it there until you pass all 3 SLAM criteria. That SLAM Process page is well done. Just don't skip anything. Make sure to inspect ANY possible hiding places in the pool for algae. Brush daily, vacuum dead algae, and clean the filter if it increase by 25%. You can do this. :goodjob:
 
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