Stabilizer in salt water pool

[kscongdon]

What is the purpose of stabilizer if I have a SWG that can generate enough chlorine to keep levels optimal even through the hot sunny Florida summer?
My pool seems to eat up stabilizer. I spent $150 on stabilizer last year for my 14,000 gallon salt water pool. Does that sound right? I'm looking for a way to reduce my spending on stabilizer.

 

[mknauss]

A good review.

CYA - Further Reading

www.troublefreepool.com

If you are using alot of stabilizer, be sure you do not have a leak. Do you also need to add a lot of salt?

Might also look at using a different CYA brand. Some have been found to not be as robust as others.

 

[kscongdon]

Thanks for the super fast reply!
Salt consumption is normal and there is no leak. I have read in the forum about poor quality stabilizer. That's probably the case here because I buy it on Amazon. How do I tell a good quality from bad?
Pool Mate 1-2607B Swimming Pool Stabilizer and Conditioner, 7-Pounds https://a.co/d/5PZLsDJ

I was going to post this next question in a separate thread because I don't think it's related, but I don't know. I do get a lot of scale on my SWG so I have to clean it every couple of weeks. Related? I've already adjusted the timers to make sure the SWG is off 30 minutes before the pump shuts off based on what I've read in this forum. Any other suggestions?

Thanks in advance. TFP has been really great since I built my pool three years ago.

 

[mknauss]

If your SWCG is scaling, you have a water chemistry problem. Your data shows a TA of 90. I would suggest getting that to 70 or a bit lower.
That stabilizer has worked for most.
I assume you are using a quality test kit. Filling out your signature helps us help you.

 

[Newdude]

Orlando averages 4 ft of rain a year, which is the better part of a free water exchange.

CYA will need replacing at a faster rate than salt and calcium because it degrades a little each month and degrades even more in the warm climates.

 

[kscongdon]

Thanks for the reminder. I filled out the profile. I use the TFP test kit.
Just for my understanding, though, why do I need stabilizer if I can generate the chlorine in need?

 

[mknauss]

Just for my understanding, though, why do I need stabilizer if I can generate the chlorine in need?

Did you read the article I linked in Post 2?

 

[mknauss]

Thanks for the reminder. I filled out the profile.

Create Your Signature - Further Reading

www.troublefreepool.com

 

[kscongdon]

Did you read the article I linked in Post 2?

I guess I can rephrase my question, why do I care if the sun degrades the chlorine if I can generate enough to keep the level good and the water clear?
I'm not really sure what the second reason for CYA (buffers the harshness) means to me as a pool owner/user. The article talks mostly about degradation so maybe this second thing is not very important?

 

[mknauss]

Harshness. If you have little or no CYA, it will be very harsh to skin, clothing, eyes, etc. Also, the half life of FC with no CYA with sun on the pool is 50 minutes. So you would need your SWCG to be able to add around 2 ppm FC per hour to your pool when the sun is out. A T9 SWCG cannot do that.

EDIT -- your SWCG will expire much sooner also. There is a finite amount of FC that can be created. If it lasts half as long as it should, that is cost too.

 

[kscongdon]

Harshness. If you have little or no CYA, it will be very harsh to skin, clothing, eyes, etc. Also, the half life of FC with no CYA with sun on the pool is 50 minutes. So you would need your SWCG to be able to add around 2 ppm FC per hour to your pool when the sun is out. A T9 SWCG cannot do that.

EDIT -- your SWCG will expire much sooner also. There is a finite amount of FC that can be created. If it lasts half as long as it should, that is cost too.

Ok, I gotcha. It sounds like my CYA consumption is reasonable and the brand I'm getting is good. I'll just buy it in larger package now so I don't have to worry about ordering it each month.

 

[JoyfulNoise]

Maybe an equation will help -

FC = active chlorine + reserve chlorine

Active chlorine = hypochlorous acid + hypochlorite

Reserve Chlorine = chlorine that is bound to cyanuric acid.

When you have no cyanuric acid in the water, all of the FC is active chlorine. At a pH of 7.5, the amounts of hypochlorous acid and hypochlorite are roughly equal. So an FC of 1ppm is equivalent to 0.5ppm hypochlorous acid and 0.5ppm hypochlorite. Hypochlorous acid is the stuff that kills everything in the water and oxidizes bather waste. If you could hold hypochlorous acid in your hand it would burn a hole through your skin, the vapors would melt your corneas and it would likely explode. Hypochlorite is the stuff your laundry bleach is made out of. Makes you whites white and cleans your clothes.

When you follow the TFP recommended FC/CYA ratio, something like 90% of the chlorine you add to the water stays bound to CYA. The rest of it is free to form active chlorine. So your active chlorine compounds are more like 0.05ppm each.

Which scenario do you think is preferable ?

Hint - it only take about 0.1ppm active chlorine concentration to kill most pathogens and keep algae from growing.

 

[Pauls234]

Salt is left behind when chlorine kills things so that is likely what is keeping your salt levels relatively stable while CYA declines with rain water replacement.