Using Caustic Soda to neutralize Cyanuric Acid

[Mdragger88]

With such a small pool you can get a drape over swg that just hangs in the pool & doesn’t need to be inline with any plumbing - check out the large ControlOmatic Megachlor.
I have a drape over (chlormaker cl02) in my pool currently but its been discontinued.

 

[Bperry]

You guys are awesome and this forum is great .
I will love to switch to a salt water chlorinated pool, but my pool is rubber lined and have zero external plumbing, just an in-pool filter.
I am not sure what CSI stands for, so sorry can't answer that James.
We have a small rain season in May, so I will change as much wayer as possible, to get the cyanuric acid level down.
Does the following sound like a good plan forward?
Keep in mind I am using rain water, so zero TA or hardness as a starting point.
1. Fresh fill of 3,000 gal water + 3 table spoons of copper sulfate + 5 lbs of baking soda.
2. Use 6 chlorine tablets over the next 6 weeks. That should bring cyanuric acid to 50 ppm, then switch to bleach.
The big question is then, how much bleach to add and how often?
The local bleach is about 5% sodium hypochlorite.
The pool is in direct sunlight all day, if that is a factor.


View attachment 473716

1. Fresh fill of 3,000 gal water + 3 table spoons of copper sulfate + 5 lbs of baking soda.
View attachment 473716

I think your picture fooled everyone to look past the copper sulphate addition? I don’t think you want that in the water. Beautiful backyard.

 

[SorensenR]

I think your picture fooled everyone to look past the copper sulphate addition? I don’t think you want that in the water. Beautiful backyard.

Ohh, no copper sulphate?
I thought it was an excellent algaecide and a tablespoon per 1,000 gal was generally recommended.
What is the downside or using it?

 

[ajw22]

Ohh, no copper sulphate?
I thought it was an excellent algaecide and a tablespoon per 1,000 gal was generally recommended.
What is the downside or using it?

You dont need algaecide when following the FC/CYA Levels with the proper FC level.

Algaecide - Further Reading

www.troublefreepool.com

Copper in Pool Water - Further Reading

www.troublefreepool.com

 

[SorensenR]

With such a small pool you can get a drape over swg that just hangs in the pool & doesn’t need to be inline with any plumbing - check out the large ControlOmatic Megachlor.
I have a drape over (chlormaker cl02) in my pool currently but its been discontinued.

This is certainly the ultimate solution . I didn't even know such a diverse existed. Many thanks for the tip.
It is even small enough so that I can place it inside the housing of the in-pool filter, to prevent damage when kids play in the pool.
Just, double checking, I assume you mean this model:

ControlOMatic Chlorine Generator MegaChlor with Chlorine Detection

Chlorine Detection Technology only produces chlorine as needed

hottubwarehouse.com

If you know a good vendor that ships overseas, please let me know.

Apart from getting salt stains around the pool, are there any downside from switching to salt water?

 

[Mdragger88]

That’s the one-
It can produce up to 100 grams or .22 lbs of chlorine per day
Which would look about like this in your pool volume

I am interested in seeing how your filter operates. Can you post some pictures?

 

[Mdragger88]

Edit *
This is the one

MegaChlor

MegaChlor pool salt water chlorine generator with Self Cleaning Reverse Polarity technology

controlomatic.ecwid.com

The one you linked is the “CD” version (chlorine detection) which sounds great but in reality it has its issues & can be finicky/frustrating.
You may try & contact ControlOmatic directly to inquire about shipping or possibly have it shipped to a family member/friend in the states who will then ship to you.

 

[SorensenR]

I am interested in seeing how your filter operates. Can you post some pictures?

It is a Desjoyaux GR.I 110 filter, using a 5 micron filter sock and rolling 18 m3/hour. Not great by any standard, but kind of OK.

 

[mgtfp]

Ohh, no copper sulphate?
I thought it was an excellent algaecide and a tablespoon per 1,000 gal was generally recommended.
What is the downside or using it?

Copper can eventually cause very ugly staining on your pool surfaces.

Chlorine in the right dosage following the
FC/CYA Levels does a much better job at algae prevention. Without side effects.

 

[Mdragger88]

It is a Desjoyaux GR.I 110 filter, using a 5 micron filter sock and rolling 18 m3/hour. Not great by any standard, but kind of OK.View attachment 474093View attachment 474094View attachment 474095

Very interesting!!

 

[SorensenR]

That’s the one-
It can produce up to 100 grams or .22 lbs of chlorine per day
Which would look about like this in your pool volume
View attachment 474086
I am interested in seeing how your filter operates. Can you post some pictures?

Quick question for M88. Do I need to run the MegaChlor unit on a timer to get the FC correct or is it on 24/7?
Do I need a separate test kit or will my trusted K2006 kit do the job?
I can get a digital salinity and float type hydrometer locally.

 

[PoolStored]

Quick question for M88. Do I need to run the MegaChlor unit on a timer to get the FC correct or is it on 24/7?

Leave it on 24/7. It has adjustable output. Say you set it for 20%, it will run 20% of the time. You find the setting that leaves the pool with stable FC.

Do I need a separate test kit or will my trusted K2006 kit do the job?

You would want to get a k-1766 salt test to test salt levels. For that test, I would recommend a smartstir.

I can get a digital salinity and float type hydrometer locally.

There are inexpensive salt test meters that can be used for quick checks of salt level. It is best to use a salt meter along with the K-1766 Salt Test kit and you will see how close your meter is compared to the K-1766 test. If the salt meter indicates a low or high salt problem you should then confirm it with the K-1766 salt test.

Get a salt meter that is calibrated for 3000 ppm of salt. You can find a discussion salt meters on the digital-salt-and-temp-tester thread

 

[SorensenR]

Use your K-2006 to test CYA. Use the dilution method:
Add pool water to bottom Line.
Add tap water to top Line.
Shake.
Pour out half so mixture is to bottom line.
Add reagent to top line.
Shake.
Test outside with back to sun and tube at waist level.
Pour back and forth a few times to see if you get the same result.
Double the result.

If you are in fact 160 CYA, you can't add enough bleach to reach an FC level to sanitize the water. FC/CYA Levels


You need to test your FC daily. Then you need to add enough to get your FC back to target range for your new CYA. I would recommend targeting the higher end of the range. For CYA 50, target is 6-8. Until you know your pool, I would target 9-10. Again this read...Link-->FC/CYA Levels

Once you understand, generally how much Bleach you need to add daily to get to your target, then you can use the pump to automate.

Do you have a smart phone? Download PoolMath. It will help you with how much 5% to add to a 3000g pool to get to your target from your FC test result!

Thanks for your detailed description PS. We have a smaller rain season in May and if I get enough water, I will do a partial refill, get cyanuric acid in the 50 ppm range, switch to bleach and follow your guidelines.
I have ordered the dosing pump and will use bleach for now. I can get it for $5 a gal and I have a nice 10 gal barrel as reservoir, to keep it running when we are not at the house.
From next season, I will then switch to salt water.
I have downloaded PoolMath, now I just need some practice in using it.

 

[Mdragger88]

Anytime you get rain attempt to drain some water from the pool to help get the cya down (put the hose/pump on the pool floor)
I assume you have a submersible pump?

 

[Mdragger88]

Also, how did you fill the pool initially?

 

[SorensenR]

Also, how did you fill the pool initially?

The house have a 10,000 gal storage tank, which easily fills during our tropical monsoon rainy season.
I capture and filter rain water through an elaborate filtration system and have an additional 20 micron filter on the house pump.
I just siphon off the water in the pool with the 2" pool hose when draining it. Keep in mind, the pool is 20 ft in the air, so plenty of drop off.

 

[Mdragger88]

I thought there may be some sort of water service you could use- if it wasn’t too cost prohibitive.
Your pool is So cool- even the picture of the filters is amazing!
Here’s hoping that you get some rain soon so you can dilute that cya!

*Until then (& after) keep fc above 7.5% of your cya to prevent nasties
See
Thread 'Chlorine/CYA Chart'
Chlorine/CYA Chart

* Do the diluted cya test to confirm your cya as @PoolStored described
Step 8

CYA - Cyanuric Acid Test

Cyanuric acid (CYA) is the chemical name for the product commonly called “pool water stabilizer” … Read more…

www.troublefreepool.com

*This will make keeping ph in check tricky but use the tips here

PH - Further Reading

www.troublefreepool.com

& pick up a ph meter as they are unaffected by the higher fc levels (these must be calibrated & checked with your drop test regularly)

Understand that All the algeacide used may be preventing some algae currently & keeping the water clear but clear water doesn’t always necessarily mean sanitary. Think of algae as the canary in the coal mine- algae in itself, though unsightly, is harmless but it’s presence is the 1st indicator that fc is too low to prevent other nasties that you can’t see. When you supress algae with algaecides you take that red flag away & may unknowingly carry on at inadequate fc levels.
You don’t want that sweet baby of yours getting ear infections, rashes, etc.

 

[Mdragger88]

You guys are awesome and this forum is great .
I will love to switch to a salt water chlorinated pool, but my pool is rubber lined and have zero external plumbing, just an in-pool filter.
I am not sure what CSI stands for, so sorry can't answer that James.
We have a small rain season in May, so I will change as much wayer as possible, to get the cyanuric acid level down.
Does the following sound like a good plan forward?
Keep in mind I am using rain water, so zero TA or hardness as a starting point.
1. Fresh fill of 3,000 gal water + 3 table spoons of copper sulfate + 5 lbs of baking soda.
2. Use 6 chlorine tablets over the next 6 weeks. That should bring cyanuric acid to 50 ppm, then switch to bleach.
The big question is then, how much bleach to add and how often?
The local bleach is about 5% sodium hypochlorite.
The pool is in direct sunlight all day, if that is a factor.


View attachment 473716

You gotta enter the contest!

We Have a Winner! - Pool of the Month (March 2023); Theme - Scenic Views

1. On the first of each month, a contest "theme" will be announced (i.e. water clarity, family fun, decking, custom features, lighting, scenery, etc) 2. Members have 10 days to UPLOAD ONE image for consideration; Photo must be related to the thread titled theme for that month. 3. Per general TFP...

www.troublefreepool.com

 

[Newdude]

You gotta enter the contest

There goes MY chance at $50.

(But it would TOTALLY be fair and square, so +1)

 

[SorensenR]

You gotta enter the contest!

We Have a Winner! - Pool of the Month (March 2023); Theme - Scenic Views

1. On the first of each month, a contest "theme" will be announced (i.e. water clarity, family fun, decking, custom features, lighting, scenery, etc) 2. Members have 10 days to UPLOAD ONE image for consideration; Photo must be related to the thread titled theme for that month. 3. Per general TFP...

www.troublefreepool.com

Thanks for the encouragement M88. I can't believe my tiny cyanuric acid saturated pool is worthy of any competition, but since this month's competition is about everything but the pool, I will thrown in a picture.
This forum and community just get better and better. Thanks guys.