Is dissolving shock in a 5-gallon bucket = store-bought liquid chlorine?

rolo1792

Member
Jun 8, 2023
8
Hartford, CT
Hi folks: first time posting here. I've read that using liquid chlorine is better than powdered shock. Can I just dissolve powdered shock in a bucket vs. buying liquid chlorine? Is that essentially the same thing? I've got plenty of drytec powdered shock and would love to put that to use first.

In case it's helpful - my FC is 2ppm (tested w/ a TF-100 kit) and based on the CYA/FC chart here I need to get to 6ppm.

Thanks!
 
Hi, welcome to TFP! No dissolving powdered shock in water would not be the same. The reason liquid chlorine is better is because it does not come with CYA (like dichlor and trichlor) or calcium (calcium hypochlorite). Both CYA and calcium are needed in a pool but only a set amount. Too much CYA makes a pool difficult to keep sanitized and algae free. Excess calcium can cause calcium scale to develop on the surfaces of the pool which causes staining and rough patches that are hard on your skin. Liquid chlorine (aka bleach) does not cause these issues.

It looks like Drytec is a calcium hypochlorite product. Whether or not you should use it depends on your pool surface type (vinyl/fiberglass or plaster) and how high your current calcium level is.
 
Hi, welcome to TFP! No dissolving powdered shock in water would not be the same. The reason liquid chlorine is better is because it does not come with CYA (like dichlor and trichlor) or calcium (calcium hypochlorite). Both CYA and calcium are needed in a pool but only a set amount. Too much CYA makes a pool difficult to keep sanitized and algae free. Excess calcium can cause calcium scale to develop on the surfaces of the pool which causes staining and rough patches that are hard on your skin. Liquid chlorine (aka bleach) does not cause these issues.

It looks like Drytec is a calcium hypochlorite product. Whether or not you should use it depends on your pool surface type (vinyl/fiberglass or plaster) and how high your current calcium level is.
Super helpful, thank you. So Drytec has CYA in it? Also I have a vinyl, 20x40, in-ground pool.

This is the chlorine I will get: Pool Essentials Chlorinating Liquid for Swimming Pools, 1 Gallon - Walmart.com
 
Look at the label on your Drytec. From what I saw online it has calcium hypochlorite. CYA (cyanuric acid) and calcium hypochlorite are not compatible chemicals so it will not contain both. FYI never combine CYA and cal-hypo in the same container. It will start a fire! You can't even use cal-hypo tablets in a floater that once contained CYA even if you wash it first.

The Pool Essentials liquid chlorine is a good choice.
 
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Look at the label on your Drytec. From what I saw online it has calcium hypochlorite. CYA (cyanuric acid) and calcium hypochlorite are not compatible chemicals so it will not contain both. FYI never combine CYA and cal-hypo in the same container. It will start a fire! You can't even use cal-hypo tablets in a floater that once contained CYA even if you wash it first.

The Pool Essentials liquid chlorine is a good choice.
Cool thanks so much!

Since it doesn't have CYA does that mean I can dilute in pool water and that should be roughly the same thing as liquid chlorine form Wal-mart? If it's better to use the Pool Essentials product LMK, I'll use that.

Sorry if this is obvious and I'm not getting it.
 
Cool thanks so much!

Since it doesn't have CYA does that mean I can dilute in pool water and that should be roughly the same thing as liquid chlorine form Wal-mart? If it's better to use the Pool Essentials product LMK, I'll use that.

Sorry if this is obvious and I'm not getting it.
No, it is NOT the same as liquid chlorine.
It is CalHypo - it contains calcium.

Use the Pool Essentials 10% from Walmart.

Post a full set of current test results using your TF-100
FC
CC
pH
TA
CH
CYA
Water temperature

Add your test kit to your signature along with model numbers for your equipment.
 
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No, it is NOT the same as liquid chlorine.
It is CalHypo - it contains calcium.

Use the Pool Essentials 10% from Walmart.

Post a full set of current test results using your TF-100
FC
CC
pH
TA
CH
CYA
Water temperature

Add your test kit to your signature along with model numbers for your equipment.
OK thank you - seems very obvious now, thanks. I'll post tomorrow when I test again!
 
Yep, it is the extra's in the pucks/powders that get you if you just blindly use them and let the extras (calcium or CYA depending on the product) build up in your pool.

Liquid chlorine is less convenient, but you are only putting chlorine into your pool.
 
You should be getting your FC into the target range for your CYA today.
Dose with liquid chlorine ASAP to keep algae from getting a foothold.

What is your CYA level from your last test?
 

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Cool thanks so much!

Since it doesn't have CYA does that mean I can dilute in pool water and that should be roughly the same thing as liquid chlorine form Wal-mart? If it's better to use the Pool Essentials product LMK, I'll use that.

Sorry if this is obvious and I'm not getting it.
No- it is not the same, it also contains calcium which makes your ch level increase.
Liquid chlorine only adds fc.
 
and based on the CYA/FC chart here I need to get to 6ppm.


Screenshot_20230304_131304_Chrome.jpg


Notice target range is 6 to 8. If you start at 6, you'll be below target range in no time, and on your way to minimum.

If you find you are losing more than 4ppm, perhaps mid summer, you need to adjust the target accordingly to stay away from min by your next test/add. The same goes for the early/late season with much less daily loss. Adjust on the fly, it's a moving target and minimum is lava.
 
View attachment 501797


Notice target range is 6 to 8. If you start at 6, you'll be below target range in no time, and on your way to minimum.

If you find you are losing more than 4ppm, perhaps mid summer, you need to adjust the target accordingly to stay away from min by your next test/add. The same goes for the early/late season with much less daily loss. Adjust on the fly, it's a moving target and minimum is lava.
Awesome, thanks for this. 6-8 seems incredibly high compared to what Leslie always tells me. In the short time that I've been on this site and using the new test kit, to quote Yoda, I need to unlearn what I have learned lol.

On a related side note, I'm so grateful for everybody's input. You've all been so helpful, thank you!
 
Hi all, just tested this morning:
FC 1.3
CC .5
Calcium 300
Alk 100
pH 7.2
CYA 60

Looks like I need a lot of chlorine.
You can’t test a value of 1.3 so either you meant 1.2 or 1.5 🤷‍♀️
Going forward, Use a 10ml sample & each drop counts as .5ppm
You need almost 3 gallons of 10% liquid chlorine to get fc in target 🎯 range .
Then tonight do an
Overnight Chlorine Loss Test to be sure nothing has started brewing while you’ve been below minimum.
Is your pool vinyl or plaster?
 
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