Understanding VS pump and SWG

[Dabrodas]

After reading through the forums and articles posted, I would like some guidance.

would I be better off running my VS pump at near max (3000 RPM) for 4 hours with my SWG at 100% to produce enough chlorine vs running my VS pump at lower (near 1700 RPM) for 8 hours with my SWG at 50%.

Pool is screened in and not much debris and now use a robot cleaner.

Trying to use my equipment the most efficiently while understanding the pros and cons of doing so since the turn over is a “myth”.

 

[mknauss]

The pump rpm, as long as sufficient to close the flow switch, has no effect on SWCG chlorine production.

So if you wish, you could run the pump for 4 hours at 100% generation on the SWCG. Do test your FC each day for awhile just before the SWCG starts for the day to be sure your FC is not falling too far with the long period of no chlorine addition.

 

[Dabrodas]

The pump rpm, as long as sufficient to close the flow switch, has no effect on SWCG chlorine production.

So if you wish, you could run the pump for 4 hours at 100% generation on the SWCG. Do test your FC each day for awhile just before the SWCG starts for the day to be sure your FC is not falling too far with the long period of no chlorine addition.

Thanks and understood. I guess I’m trying to understand the advantage of a VS and how to use most efficiently, if we really only need 4 hours of run time. Theoretically, I could run the pump for 4 hours at 1700 (closes the SWG switch) at 100% SWG and call it a day? (Of course, assuming this meets my FC needs)

The only advantage of longer run times is to skim the surface? Assuming the FC needs at met at 4 hours?

 

[chiefwej]

The amount of chlorine produced has nothing to do with the pump speed. As long as the speed is sufficient to operate the SWG, it will produce chlorine. So the most economical speed is the lowest that will dependability operate the SWG. In some systems that can be as low as 1000 rpm. Start there and increase speed until the SWG works, then set the pump about 200 rpm higher, to allow for a reduction in flow as the filter begins to get dirty. That will be your most economical speed for the SWG. However it may not be enough to provide proper skimming action in the pool.

 

[Dabrodas]

Thanks. So why not run the SWG at 100% and just have the pump accommodate the run time for FC? It seems most people suggest 50%. Wouldn’t be most efficient at 100%?

Do most have that much skimming that is required?

it’s sounding more like 30 minutes in the AM to skim at 2800, 4 hours at 1700 for SWG @100%, then 30 minutes at 2800 to skim in the PM. Anything under 2200, I don’t feel or see the flow in all my return jets so I think some higher flow rates are needed.

Am I thinking too much into it? Seems like the permutations are endless and could be messing with it for years lol

 

[Dabrodas]

The amount of chlorine produced has nothing to do with the pump speed. As long as the speed is sufficient to operate the SWG, it will produce chlorine. So the most economical speed is the lowest that will dependability operate the SWG. In some systems that can be as low as 1000 rpm. Start there and increase speed until the SWG works, then set the pump about 200 rpm higher, to allow for a reduction in flow as the filter begins to get dirty. That will be your most economical speed for the SWG. However it may not be enough to provide proper skimming action in the pool.

Also my flow switch is actually immediately after my pump, before my filter. Probably a bad spot for it!

 

[Jimrahbe]

D,

Is your pool in a screen-room? If so, that is why you think skimming is a once a day process...

I don't even have trees near me and I can fill up a skimmer basket in a couple of days or less.. I use hairnets in my skimmers and can't imagine swimming in that stuff, so for me skimming, and generating chlorine, is a 24/7 process.

There is just no right or wrong answer here.. Just do what works best for you and your pool.

Thanks,

Jim R.

 

[Dabrodas]

D,

Is your pool in a screen-room? If so, that is why you think skimming is a once a day process...

I don't even have trees near me and I can fill up a skimmer basket in a couple of days or less.. I use hairnets in my skimmers and can't imagine swimming in that stuff, so for me skimming, and generating chlorine, is a 24/7 process.

There is just no right or wrong answer here.. Just do what works best for you and your pool.

Thanks,

Jim R.

Haha, yes inside a screened enclosure and I banned the wife from having leaf-shedding plants nearby. So only thing skimming are tiny flying ants. Haven’t had to empty the skimmer basket in the 3 weeks since I’ve fired my pool service and there is still nothing in there.

Just trying to be as efficient as possible, while still maintaining a perfectly clean pool. I guess it’s all just trial and error!

here’s the latest clear water

 

[Jimrahbe]

D,

The real key here is to just make sure you always keep your FC and CYA per the saltwater section of this chart.. FC/CYA Levels

I try to keep my FC at my target or higher.. I never try to keep my FC between my target and the minimum.. The minimum is a cliff that I never want to get close to falling off.

If you do that, pump run time will not be an issue..

Thanks,

Jim R.

 

[notmycupoftea]

I never try to keep my FC between my target and the minimum.. The minimum is a cliff that I never want to get close to falling off.

Well said. That cliff is steep!

 

[neutronscott]

You can download a spreadsheet here that does math if you really want to know about electrical cost efficiency. It's the 3rd reply on the top pinned post I believe. You can plug in your pump and say 1hr at high and 3 turnovers at low. Then play with the low rpm to stretch it to 24hr total and compare the total cost to running it just half at day at a different speed, etc.

I hope to install a SWG this weekend and also thinking of upgrading to a VS just because. I am very envious of your enclosure. Had to put mine in the middle of 5 trees and it's a battle! Pine cones, straw, leaves, twigs, and soooo many beetles.

 

[Dabrodas]

Thanks guys! Still working on locking it in based on my equipment. It is cool seeing a steady drop off of the FC from my SLAM (has dropped from 20 to 11 over a couple weeks), while still using a 50% output of the SWG. Once I get my FC back to 8-9, going to boost it up and see if the 6 hour run time I am doing now will be sufficient or if I will need more time.

I will definitely have to check out that spreadsheet!