SWG recommendation for 25,000 gallon pool?

[Option]

Hello,

I'm doing preliminary research on installing a saltwater generator for my in-ground pool. The pool's shape makes it difficult to get a easy approximation on capacity but I've had two pool professional take some basic measurements and both estimated around 25,000 gallons. Assuming they are correct, can anyone tell me what capacity SWG I should be looking to buy? I've seen posts on this forum recommending at least twice the pool's capacity but I am having trouble finding SWG's rated for more that 40,000 gallons.

- My VSP currently runs 12 hours a day with the first two hours running at a higher speed to accommodate the Polaris 380 booster pump (if that matters).

- Also, I'm located in Northern California and the pool gets midday sun but has lots of shade in the morning and late afternoon. Lastly, there is a ton of leaves/pollen/etc dropped in the pool during the spring/fall/winter from nearby vegetation but it only needs minimal cleaning in summer months.

 

[jblizzle]

Welcome to TFP!!!

A 40k cell is reasonable for a 25k pool. You have the advantage of already having a VS pump, so possibly having to run the pump longer so that enough FC is generated may not be that big of a deal.

The 40k cells (well Hayward at least) can make 1.4 pounds of chlorine gas in 24 hours at 100% output.
For your 25k pool, that is equivalent to 6.7ppm of FC
A typical pool needs 2-4ppm of FC added each day.
So, you would be looking at having to run it on 100% output for about 12 hours a day, and you are running your pump that long now anyway.

FYI, there is no need to run the pump at a higher speed for the cleaners booster pump, although you might want the higher speed to make that skimmer work better as needed for the leaves, etc.

 

[chiefwej]

Do you have or are you planning to add any automation system? If so that will be a factor in selecting a SWG. As far as sizing, a 40k rated system may work fine in a 25k pool, particularly if you have a VS pump. One of the most recommend units is the Hayward AquaRite AQR 15. I had one for about 12 years and wouldn't trade it for anything.

 

[Option]

Thanks for the warm welcome and quick reply!

I have read suggestions that people consider a large enough SWG so that it doesn't have to run at 100%. Their reasoning is that running an SWG at a lower capacity may significantly increase it's lifespan so, while the larger SWG may cost twice as much up front, it will likely last more than twice as long. Is there any validity in that?

Also, thanks for the tip about my VS pump not needing to run at a higher speed. It was setup that way when I moved in and it spools up for a minute before the booster kicks on so I assumed it was necessary to prime the booster.

 

[Option]

Do you have or are you planning to add any automation system? If so that will be a factor in selecting a SWG. As far as sizing, a 40k rated system may work fine in a 25k pool, particularly if you have a VS pump. One of the most recommend units is the Hayward AquaRite AQR 15. I had one for about 12 years and wouldn't trade it for anything.

Good Point! I was considering doing solar heating with a control panel to regulate the temperature. My understanding is that the solar control panel would take over the timing duties for both my VS and booster pump. Would the SWG need to be the same brand as the solar control panel to avoid the need for a separate SWG controller?

 

[jblizzle]

I tend to think that a SWG cell will generate a certain amount of FC, regardless of the % output (although there are other factors).
You need Xppm of FC added daily. It does not matter if you run 100% for a short time or 50% for double the time, you have made the same amount of FC and shortened the life of the cell the same amount.

The larger cells have the ability to make more FC. So you can run them less daily and thus they should last longer. This is independent of the % setting you use.

There are companies that make 60k cells which would likely last longer than the 40k cell, but whether that added time offsets the added cost is really hard to know ... I think generally we believe that it is worth $ the larger cell, but no real scientific proof.

- - - Updated - - -

If you are going automation, you almost MUST match that with the brand of your VSP (please add your details in your signature) to maintain full control. And most automation systems have solar capability and SWG control built-in.

I was in a similar position as you. I knew I wanted to add solar control and wanted to add SWG. For a fairly similar price and buying those separately, I decided to get the Hayward Pro Logic which controls both. Just had to buy the SWG cell and install kit and plug it into the Pro Logic.

 

[Option]

If you are going automation, you almost MUST match that with the brand of your VSP (please add your details in your signature) to maintain full control. And most automation systems have solar capability and SWG control built-in.

I was in a similar position as you. I knew I wanted to add solar control and wanted to add SWG. For a fairly similar price and buying those separately, I decided to get the Hayward Pro Logic which controls both. Just had to buy the SWG cell and install kit and plug it into the Pro Logic.

Thank you again for all the great info! Per your suggestion, I have added a signature with my pool's info. The house came with that VS pump and I believe it is only about three years old so I'd like to avoid replacing it if possible. It has it's own built-in timer/controller which is actually pretty nice (see signature link) and it even powers the booster pump. Unfortunately, if I want to keep that pump with an automation system, it seems I'd have to replace the pump's built-in control with the following automation adapter kit.

https://www.centuryelectricmotor.com/2730_V-Green_Auto_Adapter_Inst_UM.pdf
​

It has four digital inputs each with it's own potentiometer (to control speed) but I noticed the first of the four inputs also accepts a PWM signal. Can anyone tell me if that PWM signal connection means a third-party automation controller can directly control the pump's speed allowing me to ignore the other three inputs and potentiometers?

 

[jblizzle]

Well, I think you might have just started asking questions that are over the collective heads of 99.9% of the members here

I am not familiar with that VS pump or what would be required to interface it with an automation system.

 

[Option]

Well, I think you might have just started asking questions that are over the collective heads of 99.9% of the members here

I am not familiar with that VS pump or what would be required to interface it with an automation system.

Oh no! Should I repose that particular question as a new post in the "Everything Else" forum? (since that seems to be the place automation discussions?)

 

[jblizzle]

Generally we like to keep threads together if the topics are related, but, if you started a new thread asking that specific question (which is different than the SWG question, it might get more eyes on it.

Although, honestly, I am not sure if anyone will be able to help, we struggle with lack of members knowledgeable with automation systems.

 

[Option]

Generally we like to keep threads together if the topics are related, but, if you started a new thread asking that specific question (which is different than the SWG question, it might get more eyes on it.

Although, honestly, I am not sure if anyone will be able to help, we struggle with lack of members knowledgeable with automation systems.

Okay, thank you! I will post in this thread again if/when I have additional SWG questions.