Cannot measure FC after Jack's Magic Copper stain treatment-ugh!!

[CatDr]

Washing soda is also know as sodium carbonate or soda ash.

Borax is sodium tetraborate.

Borax it is then

So something is chewing thru my chlorine and dropping my pH

This am
FC 3.0. CC 5.0 pH 7.2 TA 70

Added 2 gallons of bleach

This pm
FC 4.5 CC 3.0 pH 7.0 TA 60

Is the problem all the bleach I’m adding to keep the TC at 20 for the SLAM?

 

[JamesW]

Possibly the sulfamic acid breaking down.

In my opinion, baking soda is the best thing to use with the fewest side effects and the fewest risks.

 

[JoyfulNoise]

Sulfamate eventually hydrolyses into ammonium bisulfate.

H3NSO3 + H2O → [NH4]+[HSO4]−

The bisulfate anion is acidic and reduces pH. As chlorine attacks the ammonium cation to oxidize it into nitrate and then nitrogen, those reactions are very acidic too.

So you probably need to keep your TA elevated to help reduce the pH drop caused by the oxidation of sulfamate from chlorine.

The good news is your CCs have come way down so you’re nearing the end of your sulfamate contamination and should be holding FC better.

 

[JamesW]

Sulfamic acid is a strong acid and one hydrogen comes off as soon as the sulfamic acid is added to water.

The other two or three hydrogens get released when the chlorine attacks the nitrogen and takes its electrons.

 

[JamesW]

Why Does pH drop When Treating Ammonia With Liquid Chlorine?

Oxidizing ammonia creates acid by releasing hydrogen.

More than 95% of ammonia is in the form of the ammonium ion (NH4+)

2NH4+ + 3OCl- --> N2 + 3H2O + 2H+ +3Cl-

When adding 12.5% sodium hypochlorite (liquid chlorine) to a pool to oxidize ammonia, every gallon of liquid chlorine will create the equivalent of 15 ounces of 31.45% hydrochloric acid.

10 gallons of 12.5% liquid chlorine added to 25,000 gallons of pool water with ammonia will lower the TA by about 23 ppm or the equivalent of adding 150 ounces of full strength 31.45% muriatic acid.

Every 8.53 gallons of 12.5% liquid chlorine is equivalent to about 1 gallon of 31.45% acid.

Ammonia - Further Reading

www.troublefreepool.com

 

[CatDr]

Oh now my brain hurts
Long time since undergraduate chemistry

So… keep adding chlorine to keep TC at 20
And keep adding baking soda to keep TA at say 70 to 80
Should I be adding Borax? Or will that slow down the salamis acid degradation?

 

[JoyfulNoise]

… Or will that slow down the salamis acid degradation?

Salami is for Italian grinders … hopefully you didn’t add any salami to your pool

Forget the borax and stick with baking soda for now. Once your CC’s get to 0.5ppm or lower, you can bring the FC down to a more normal range.

Keep your TA at 80ppm to help offset the acidity.

 

[CatDr]

Salami is for Italian grinders … hopefully you didn’t add any salami to your pool

Forget the borax and stick with baking soda for now. Once your CC’s get to 0.5ppm or lower, you can bring the FC down to a more normal range.

Keep your TA at 80ppm to help offset the acidity.

Hay everyone likes a salami
Maybe just not in the pool

I’ll keep adding the chlorine and Baking soda

Anyone notice Clorox is not sold in gallons anymore?!

 

[JamesW]

As the sulfamic acid hydrolyzes, the bond between the sulfur and the nitrogen breaks and the sulfur atom picks up another oxygen, which leaves two hydrogen ions as it takes the oxygen from the water.

NH₂SO₃^- + H₂O --> NH₄⁺ + SO₄^2-

Sulfamic acid + water --> ammonium ion + sulfate ion.

The hydrogen connected to the oxygen disassociated when the sulfamic was dissolved in the water.

The Nitrogen picks up two hydrogen to become an ammonium ion NH₄⁺

The 4 hydrogen are released as the nitrogen gets oxidized.

 

[JoyfulNoise]

Hay everyone likes a salami
Maybe just not in the pool

I’ll keep adding the chlorine and Baking soda

Anyone notice Clorox is not sold in gallons anymore?!

Best to not use Clorox products of any kind. Their laundry bleach contains surfactants that can cause foaminess or clouding in pools. Stick to chlorinating liquid for pools.

 

[CatDr]

Best to not use Clorox products of any kind. Their laundry bleach contains surfactants that can cause foaminess or clouding in pools. Stick to chlorinating liquid for pools.

Will do in the future
I do avoid the no splash kind in favor of the regular disinfecting

 

[JoyfulNoise]

Will do in the future
I do avoid the no splash kind in favor of the regular disinfecting

All retail laundry bleach is essentially manufactured by the same industrial supplier. Anything that says “Fabric Protection Technology” refers to the Clorox Corporation’s CloroMax technology. It has been licensed for use by almost all retailers in the US because Clorox pretty much controls the consumer bleach market. CloroMax is the addition of a alkaline and oxidizer stable poly ionic surfactant chemical. It’s added to the bleach to leave behind a residue in clothing and on surfaces that resists staining and microbial contamination. It supposedly reduces the need for higher concentrations of bleach to do the same cleaning job. This is how Clorox moved from bleach products being nominally 8.25% to 6% bleach (and charging more money for smaller product volumes, ie, “gallon” jugs that are 100 fl oz versus 128 fl oz).

Long story short - you don’t want CloroMax in your pool.

 

[CatDr]

All retail laundry bleach is essentially manufactured by the same industrial supplier. Anything that says “Fabric Protection Technology” refers to the Clorox Corporation’s CloroMax technology. It has been licensed for use by almost all retailers in the US because Clorox pretty much controls the consumer bleach market. CloroMax is the addition of a alkaline and oxidizer stable poly ionic surfactant chemical. It’s added to the bleach to leave behind a residue in clothing and on surfaces that resists staining and microbial contamination. It supposedly reduces the need for higher concentrations of bleach to do the same cleaning job. This is how Clorox moved from bleach products being nominally 8.25% to 6% bleach (and charging more money for smaller product volumes, ie, “gallon” jugs that are 100 fl oz versus 128 fl oz).

Long story short - you don’t want CloroMax in your pool.

Thanks for the heads up
Most other threads here talk about using bleach. I’ll go get the yellow jugs of chlorine from the pool store this weekend

Funny the more I try and fix my pool the more issues I seem to create

Eventually I’ll learn enough to fix more than I break

 

[JoyfulNoise]

Thanks for the heads up
Most other threads here talk about using bleach. I’ll go get the yellow jugs of chlorine from the pool store this weekend

Funny the more I try and fix my pool the more issues I seem to create

Eventually I’ll learn enough to fix more than I break

Back in the day, “bleach” and “liquid chlorine” were synonymous. Not so anymore. I try to refer to using “liquid chlorine” in pools and no longer recommend laundry aisle bleach use in pools. If you have to pay a premium by purchasing pool store chemicals then it’s worth it to not roll the dice and add unknown chemcials to your pool.

 

[CatDr]

Back in the day, “bleach” and “liquid chlorine” were synonymous. Not so anymore. I try to refer to using “liquid chlorine” in pools and no longer recommend laundry aisle bleach use in pools. If you have to pay a premium by purchasing pool store chemicals then it’s worth it to not roll the dice and add unknown chemcials to your pool.

Agreed. I know too well the problems with “mystery” chemicals. Ie Jacks magic

In the long term I won’t need much chlorine as I have a SWG

 

[CatDr]

Agreed. I know too well the problems with “mystery” chemicals. Ie Jacks magic

In the long term I won’t need much chlorine as I have a SWG

Looks like I have turned the corner

Today:
FC 13
CC 1.0
pH 7.4
TA 90
CH 225
CYA 50
Salt 3000
Temp 85F
CSI -0.42

I have a few “yellow” spots that brush off easily

I added enough chlorine to raise FC to 20 to continue the SLAM

Moving forward:

Continué SLAM until no more yellow forming , the water is clear, CC is 0.5 or less and it passes the OCLT?

Should I increase my CH? It does not seem to rise on its own due to LOTS of rain-maybe even a hurricane next week

Thanks for all the help

Matt

 

[JamesW]

Should I increase my CH? It does not seem to rise on its own due to LOTS of rain-maybe even a hurricane next week

You can increase the CH some to help the CSI.

Also, allow the pH to rise to about 7.8, but don't add anything to raise it; it will increase on its own.

 

[JoyfulNoise]

Agreed. Basically just follow the SLAM process through to completion. Could be tough getting that last little bit of CCs to below 0.5ppm but give it a few days and see how it goes. Lots of sunlight can help too so uncover the pool if you use any kind of cover.

 

[JamesW]

Interesting about the pH and TA drop right before the CC cleared.

This can help identify when the sulfamic is beginning to break down.

 

[JoyfulNoise]

Interesting about the pH and TA drop right before the CC cleared.

This can help identify when the sulfamic is beginning to break down.

The clearing time for sulfamic acid contamination is going to be dominated by the hydrolysis of the sulfonyl bond. Normally the hydrogen atom can hop between living on the sulfur side of the atom (bonded to oxygen) or on the nitrogen as —NH3 atom creating an excess positive charge on the nitrogen (zwitter ion). Chlorine atoms attach to the nitrogen moiety either as monochloro- or dichloro- . My guess is that when the chlorine bonds to the nitrogen, the hydrogen atom stays with the oxygen on the sulfur group and that slows down the hydrolysis of sulfamate into bisulfate and ammonium.

It could be that the presence of chlorine actually makes the sulfamate stay around longer. An interesting experiment would be to see if adding peroxide instead of chlorine to sulfamic acid contaminated water speeds up the hydrolysis of sulfamate. Perhaps that’s a way to get rid of it faster