Cl / swg / cl use in pool

[jeremycrook]

I have a few questions regarding my SWG and CL. I have noticed that my CL consumption has definitely fallen due to the change in weather. My SWG was set to 50%, and kept a nice ~7 and has rose due to what I believe is the temp change. Does the temperature effect this solely, or is the lack of sun during the daylight hours, lack of bodies in the pool with sunscreen, all the above? My CL level rose above the 7 mark and I shut off the SWG, the level really hasn't budged much, only dropping slightly within almost a week of the SWG being turned off.

This leads to my second question: At what point exactly should I turn off the SWG for the winter? Is it the ambient temp being ~50 deg outside? Or the water temperature of the pool being ~50 deg? I have a friend that says his SWG will work throughout the winter, he states his unit produces CL. I want to do whatever it takes to extend the life of my SWG, so what's best?

I assume as the temperature of the water is getting cooler, the CL lasts longer. (this may be wrong) But can I safely assume I can add bleach to a certain % once a week and keep my FC level decent? (each Sunday add 2 or 4 cups?) This is a guess but I am sure poolmath can give me a number?

 

[JoyfulNoise]

In the fall/winter months with cold water and less incident UV, FC consumption falls off very rapidly. Once my pool water goes below 65F, my daily FC loss rate is immeasurably low, somewhere around 0.1ppm/day.

Most SWGs don’t run below 56F and almost all of the major models have a COLD WATER cutoff to protect the cell plates from damage. Simply run your SWG at lower % output until you start seeing a consistent cold water cutoff and then turn it off. Some people will winterize their pools and bring their SWGs indoors while installing a dummy tube in place of the SWG.

It is perfectly OK to add whatever amount of bleach your pool needs over the winter. Last winter (4 months around here), I used exactly 1 whole gallon of bleach in my pool. Nothing else was needed.

 

[Jimrahbe]

Jeremy,

As you said.. "All of the above" will reduce your chlorine demand.

Most salt cells shut off when the water temperature gets below about 52 degrees. I have not heard of one that works when the water is colder than 50 degrees. Most systems have a light, or code, that tells the operator that the cell is off due to low temperature.

In any case, it matters little, because once the water gets to 50 degrees not much grows in it anyway.

Your plan to add liquid chlorine once a week in the winter should work just fine. I would always test and then add only the amount of chlorine that is required.

I usually only use a couple of gallons of chlorine over the entire winter.

Thanks for posting,

Jim R.

 

[jeremycrook]

In the fall/winter months with cold water and less incident UV, FC consumption falls off very rapidly. Once my pool water goes below 65F, my daily FC loss rate is immeasurably low, somewhere around 0.1ppm/day.

Most SWGs don’t run below 56F and almost all of the major models have a COLD WATER cutoff to protect the cell plates from damage. Simply run your SWG at lower % output until you start seeing a consistent cold water cutoff and then turn it off. Some people will winterize their pools and bring their SWGs indoors while installing a dummy tube in place of the SWG.

It is perfectly OK to add whatever amount of bleach your pool needs over the winter. Last winter (4 months around here), I used exactly 1 whole gallon of bleach in my pool. Nothing else was needed.

Ok this makes sense then why my FC level is still quite high. Can I purchase the dummy tube online, or is that something that I need to make?

Jeremy,

As you said.. "All of the above" will reduce your chlorine demand.

Most salt cells shut off when the water temperature gets below about 52 degrees. I have not heard of one that works when the water is colder than 50 degrees. Most systems have a light, or code, that tells the operator that the cell is off due to low temperature.

In any case, it matters little, because once the water gets to 50 degrees not much grows in it anyway.

Your plan to add liquid chlorine once a week in the winter should work just fine. I would always test and then add only the amount of chlorine that is required.

I usually only use a couple of gallons of chlorine over the entire winter.

Thanks for posting,

Jim R.

Ok, so if nothing really will grow in the winter time, am I still going to adhere to the CYA / FC levels? Or can I just shoot for having a small amount of FC in my pool at all times (~3ppm)?


THANK YOU BOTH FOR REPLIES!

 

[JoyfulNoise]

Check with Jandy. I have a Pentair SWG and Pentair sells a dummy tube with the correct fittings for startup & winterization purposes. I live in an area with very little freeze danger so I’ve only used mine a few times. I imagine they are more useful in areas where freeze damage is a concern.

 

[Jimrahbe]

Ok, so if nothing really will grow in the winter time, am I still going to adhere to the CYA / FC levels? Or can I just shoot for having a small amount of FC in my pool at all times (~3ppm)?

Jeremy,

I don't care want the temperature is, I always try to stay above the minimum level in the FC/CYA chart.

Jim R

 

[jeremycrook]

Jeremy,

I don't care want the temperature is, I always try to stay above the minimum level in the FC/CYA chart.

Jim R

Will do, thank you all.