Downsides of SWGs - fact or fiction?

[ValleySooner]

My pool construction was completed earlier this month... and I'm gradually learning more and more about the technology, chemicals, and process needed to properly maintain it. Due to rising CYA with continued usage, I've switched from using trichlor pucks to liquid chlorine. However, I usually end up adding about a gallon of 6% bleach a day. It's not difficult, but if you're busy and don't get around to it, then you'll end up with a problem pretty rapidly.

In that light, i started thinking 'salt'. When I asked my pool builder whether he had installed a Jandy AquaPure previously, he replied:

You don't want a salt system. Reasons I don't like salt: it will raise the PH in your water to above 7.6 and you will have to add a lot of acid to keep it down. This will eat your plaster and make it rough. Also it will leave deposits all over your tile and inside your equipment, very bad. Finally, salt is very corrosive by nature and it will damage your flagstone and decks surrounding your pool. These are the realities of salt systems.

I know you have to add acid frequently when using an SWG with a high TA and no borates. However, with proper balance, can you get by with weekly additions of acid? As long as my ph is in balance, my plaster will be okay, won't it? Will a 3000ppm salt load leave damaging deposits in my equipment as suggested above? Without proper balance and care, any system can be "bad." I'm just trying to sort through the facts and fiction of using an SWG.

Thanks for any advice/input you can provide!

 

[frustratedpoolmom]

Sounds like you already answered your own question.

Yes, if you maintain the recommended levels for SWGs as posted in Pool School, your PH and your plaster should be fine.

Many users successfully use salt, seems to me your pool could be one of them...

Without proper balance and care, any system can be "bad."

You said it.

 

[dudeguy37]

Just about everything your builder has mentioned is pretty dang accurate. The main thing with salt systems is that you understand what you're getting: Nice feeling water; nothing more. From what I've found, keeping a TA of about 60-80 keeps the pH slighty more under control, but you're still adding acid every 7-10 days. As far as the deposits in the filter/equipment/etc., well, yes and no. The key thing is keeping your pH under control A consistently higher pH will harden up minerals (calcium), and you tend to get much more scale on tile, equip., etc. than usual. You can either use a scale preventer, or just keep your pH between 7.2 and 7.6, which isn't fun with salt. Also, keep in mind that swgs are a great idea, but not perfected (like many things in life). By the time you think you might be about to start making up your chlorine costs, your cell's gonna die ($400-800, roughly). Average life is typically only 2-4 years, but all the manufacturers LOVE to claim more. Cleaning the cell (usually every 3-6 months) wears it down faster, too. The water feels nice, though Hope that helps you in your decision making process...

 

[Guest]

Just about everything your builder has mentioned is pretty dang accurate. The main thing with salt systems is that you understand what you're getting: Nice feeling water; nothing more. From what I've found, keeping a TA of about 60-80 keeps the pH slighty more under control, but you're still adding acid every 7-10 days.
I add acid every 2-3 months in a pool that is open year round. TA at 70, CYA at 80, and borates at 50 ppm. Many of my customers also reported the same acid demand with a SWG and similar parameters (and pool surface does not seem to be a major factor once you have cured plaster). You might want to read this:
water-balance-tips-for-a-swg-t3663.html

As far as the deposits in the filter/equipment/etc., well, yes and no. The key thing is keeping your pH under control A consistently higher pH will harden up minerals (calcium), and you tend to get much more scale on tile, equip., etc. than usual. You can either use a scale preventer, or just keep your pH between 7.2 and 7.6, which isn't fun with salt.
Actually, If you keep the CYA at the top of the recommended range and keep the TA low (and add borates), pH control is pretty easy with a SWG!

Also, keep in mind that swgs are a great idea, but not perfected (like many things in life)
Then again, SWGs have been in general use almost as long as stabilized chlorine has. Both surfaced in the 60's!
. By the time you think you might be about to start making up your chlorine costs, your cell's gonna die ($400-800, roughly). Average life is typically only 2-4 years, but all the manufacturers LOVE to claim more.
And the cost of stabilized chlorine, pH increaser, and alkalinity increaser (along with the algae3cides, shock, clarifier, etc. that the average pool owner uses) during that time frame is going to be in the same ball park so this is really a break even.
Cleaning the cell (usually every 3-6 months) wears it down faster, too. The water feels nice, though Hope that helps you in your decision making process...

My Goldline cell is going into it's 5th year and still going strong. I have had the clean the cell once since it was installed (but I do inspect it regularly). Also, you have to figure in the convenience feature into the cost of the SWG. THAT is a very big part of the appeal. Personally, I would never go back to manually chlorinating nor would I consider persitatic pumps with or without ORP (having used such systems on commercial pools.)

IF you understand what is happening in the pool and why it's easy to maintain the pH in a salt pool AND keep scale from building up.

Do I think SWGs are a good idea? You bet!

 

[Lana537]

Loving our SWG!

Waterbear is a tough act to follow, but I must say we are loving our new Pool Pilot Digital.

Before we found an area provider to order and install ours, we met with firm resistance from the old timer who had been taking care of our pool for the previous owners. I can see a scenario where all could have gone horribly awry if we had gotten our SWG but had NOT discovered Trouble Free Pool and the wizards who live here.

Our pool has been solid as a rock--stable, happy, and crystal clear. The Pool Pilot keeps the FC right on target 5; the TA is around 85, and that pH sits pretty at 7.4. The pool will go for weeks like this (until DH gets adventuresome and says let's see what "Boost" will do.....) and it took me just a little time (and one small dose of MA) to get the pool settled back down to humming nicely along....

This may sound crazy, but I don't care if I have to replace that Pool Pilot in 3 years--we do run the pump 24/7, because this makes DH happy. The SWG combined with BBB has made everything so easy and simple. It is a small luxury I'm glad we were able to afford.

To the OP--you did right to come here to this site for info and opinions.

Good luck~

Lana

 

[duraleigh]

As an owner of a pool without an SWG, I would tend to agree with waterbear.

That said, dudeguy and your PB both have some points that can be troublesome if you do not manage your pool water

I would never underestimate the convenience factor of an SWG. To me, that's the biggest selling point and it's darn valid. So, if you manage your pool properly, the SWG is worth it. If you fail to manage it, you may experience some of the pitfalls that dudeguy and your PB talk about.

Possibly because SWG's can appear so troublefree, it's a little easier to overlook the routine tests and pool water management that need to be done regardless of how you chlorinate your pool.

 

[anonapersona]

I've got a question for all of you. In an area where water has high TA, like fill water with TA of 300 or higher.... does this set one up for difficulties with the SWG?

You'd be back to adding acid really often to keep TA and pH under control whenever you had evaporation or splashout and had to refill some.

And, might the resulting fluctuation of pH as you try to lower pH then do damage to rockwork around the pool?

 

[JasonLion]

Rising PH is a common problem with SWG pools for people who don't follow our advice on water balance. If you follow our advice it is a totally different story. I haven't had to adjust my PH yet this season, it is sitting at 7.5 and hasn't moved at all in weeks. My cell is three years old and looks just like the day I bought it. I am not sure just how long it will end up lasting, but the way things have gone so far I expect it to last quite a while.

anonapersona, things are much more challenging if your fill water has high TA and you live in an arid area with rapid evaporation. Even then, if you don't have too much aeration, it is possible to keep PH increases under control by keeping TA as low as practical and adding borates.

 

[dudeguy37]

My apologies, Waterbear. I did not gear my advice toward the few people who actually care to research anything (TFP users). I work with customers and clients around the L.A. area; fast paced, instant gratification lifestyles for the most part. So, all I ever deal with on swgs, day in and day out, are problems. SO, if done as you do, SWG's would be great! If I tell my customers (even the DIY-ers), or write out instructions for even the simplest things, I usually get these blank stares... I'm happy to work for a new pool company, though, where the customers just tell us to "do what needs to be done," rather than the thousands of DIY-ers with NO experience I had to re-explain EVERYTHING to, regularly! If only every DIY-er used TFP...

 

[mas985]

anonapersona, things are much more challenging if your fill water has high TA and you live in an arid area with rapid evaporation. Even then, if you don't have too much aeration, it is possible to keep PH increases under control by keeping TA as low as practical and adding borates.

That is exactly my situation but unfortunately I haven't been so lucky. Even using all the recommended techniques, my PH keeps rising. The only solution for me was a constant acid drip. Our fill water is so high in TA (>200 ppm) and evaporation also very high (>2" per week) and we have no rain to speak of during the summer that I cannot keep TA below about 80 ppm. I end up using about 2 gallons of acid per month to keep PH at about 7.5.

But even with that, it is a very small price to pay to have the convienence of a SWG. I would probably still make the same decision. Handling 2 gallons of acid a month is no comparison to the many gallons of chlorine (10+) that I would have had to deal with if using BBB.

 

[Strannik]

If only every DIY-er used TFP...

what stops you from giving them the card with address?

 

[CarlD]

To follow Duraleigh, Waterbear and Jason:

It's clear that with SWGs it's VERY important to keep T/A at the low end of the range or lower (around 80ppm) or you'll face the constant rising pH problem. Plus, the higher CYA levels seem to also be critical to good SWG maintenance and performance.

As for the salt being a problem for corrosion--again, it's a matter of maintenance. If you can taste the salt in the water, it's probably higher than you need--and the saltier, the more corrosive it is.

If your fill water is really too high in T/A for you to maintain, then perhaps you should consider one of the automatic systems for injecting liquid chlorine. Since SWGs run $1000 or more, that gives room in the budget for something like a peristaltic pump on a timer. You'll have to figure out your daily chlorine demand, the capacity of the pump (they come in a range of sizes) and how long it should run every 24 hours. Be forewarned: LC systems can scale up, too.

Personally, I'm biased against pool stores and pool installers--they all have an angle (except the guys who post regularly here and at PoolForum), and will say ANYTHING.

I don't have an SWG, but after reading about them nearly daily for about 8 years, I think the MAIN issues are:

Is the cost for convenience trade-off worth it to you?

and,

Which one to get?

For me, so far, the equation has been for adding LC manually. This season has been weird. We've had SO much rain that I have trouble maintaining my T/A and CYA levels--it just keeps washing out--we have had incredible cloudbursts nearly every day. Therefore, for the first time in 10 years of pool ownership, tri-chlor pucks in a floater have been the ideal solution. Crazy, isn't it? But for THIS season, it's working!

The pucks maintain a relatively constant FC level through days where the pool stays covered, they add needed CYA that I keep losing from the storms. The pucks drive the pH down, so I add Washing Soda to balance it and that adds the needed T/A as well. Washing Soda is cheap--it's the same as Soda Ash or "pH Up!" but costs NOW about $.98/lb--it used to be about $.79/lb.

So, for THIS season it works. If next year we have a nicer spring and a drier summer as we usually do, I won't be using pucks because they won't be appropriate. Plus, one medium size bucket has lasted this long--from the beginning of the season to the end of July. Yes, it's more expensive than LC and adding CYA, but it's much more convenient....For THIS year. (Using PoolLife pucks--I want to make sure I don't get copper in them).

 

[DaveNJ]

My pool was built in 2005 (PF days), maintained the water to industry levels. I was adding 16oz. of acid a week. After adjusting my levels to the reccomendations here I add acid about once a month. It is very easy to get lax with testing the water.

 

[Brad S]

I keep a TA around 70, and run the SWG about 2.5-3 hours out of every 24 (the pump runs 15 hours a day and the SWG is set on 15-20%. This keeps about 5 ppm chlorine in the pool at all times, even with a pretty heavy swimmer load. I keep the CYA at the lower end of the pentair recommend (they recommend 50-80) and never had a problem. Mine is pretty oversized for my pool and i dont have to run it that much to keep a constant level of chlorine. So..my pH doesnt rise as fast and i can run a lower CYA level. I live in new england and dont have the constant summer sun so YMMV there if you live in the south. My acid use is pretty low too. I havent added any acid in about 3 weeks and my pH is steady around 7.6. I wonder how much people consider "a lot of acid". Even if i added a couple cups every 7-10 days or so, i would not consider that a lot.
I havent noticed any salt build up anywhere either. I keep it around 3200 ppm so i cant even taste it.
I didnt get it for cost savings. Its convenience. Even if i had to replace the cell in 2 more seasons, the 500 bucks or so it will cost doesnt compare to having to fool with bleach, dichlor, triclor, etc

 

[DBfan187]

I wonder how much people consider "a lot of acid". Even if i added a couple cups every 7-10 days or so, i would not consider that a lot.

I have lots of customers who use up to or more than half - 3/4 a gallon a week.

 

[Guest]

I wonder how much people consider "a lot of acid". Even if i added a couple cups every 7-10 days or so, i would not consider that a lot.

I have lots of customers who use up to or more than half - 3/4 a gallon a week.

Then again, I have seen this much acid usage on pools using sodium hypoclorite or cal hypo. Once again, you can usually find too high a TA and more than average aeration the culprit (assuming cured plaster or a non reactive pool surface).

 

[crabboy]

Now in my third year of pool ownership I rarely have to add acid to my pool anymore. My TA is about 60-70 and I try to keep the pH around 7.2-7.5. As for purchase, operational and maintenance costs, I don't care, not having to add chlorine by hand is priceless. I do notice that the grass downhill from my overflow is not doing as well as the rest of the lawn. The salt does have an impact there.

 

[captfun]

Finally, salt is very corrosive by nature and it will damage your flagstone and decks surrounding your pool. These are the realities of salt systems.

This is the one thing that sticks out over the others. Splash out on the flagstone can be a real issure with saline systems. There a quite a few builders in Texas that won't deal with SWG's and flagstone together, as the salt will etch and pit the flagstone something fierce.

 

[anonapersona]

Finally, salt is very corrosive by nature and it will damage your flagstone and decks surrounding your pool. These are the realities of salt systems.

This is the one thing that sticks out over the others. Splash out on the flagstone can be a real issure with saline systems. There a quite a few builders in Texas that won't deal with SWG's and flagstone together, as the salt will etch and pit the flagstone something fierce.

OK, now the question for those of us in Texas who have flagstone but do not have SWG's... how much salt does it take to have this effect?

I can see my waterfall is decaying, I see sand in the pool below it -- is it the salt I have due to bleach or is it due to adding MA to control pH?

 

[Guest]

Finally, salt is very corrosive by nature and it will damage your flagstone and decks surrounding your pool. These are the realities of salt systems.

This is the one thing that sticks out over the others. Splash out on the flagstone can be a real issure with saline systems. There a quite a few builders in Texas that won't deal with SWG's and flagstone together, as the salt will etch and pit the flagstone something fierce.

It seems the easy answer would be to NOT use flagstone in pool construction. I live on the coast (actually half a block from the Atlantic and even closer to the Intercoastal Waterway) and all construction, pools included, is designed to withstand salt (we get salt on EVERYTING!). There are many pool buidling materials that are basically impervious to the effects of salt.