Salt for salt water pool

[Suandpete]

We have been running our salt water pool for a number of years now using salt pastilles produced specifically for swimming pools.  Just wondering if anyone uses water softening pastilles?  On the bag it says Chlorure de Sodium. Are there likely to be any problems if that is used instead?

[Théière]

Although not a fan of salt water pools, yes you can use the softner salt.

http://www.youtube.com/watch?v=BC9ITqu0V9o&feature=player_embedded

You can tell a salt water pool by looking at the water, it's that greyish, brackish, tint.

[AnOther]

[quote user="teapot"]You can tell a salt water pool by looking at the water, it's that greyish, brackish, tint.[/quote]Mine isn't, it's still crystal clear even having sat through the winter covered but static [;-)]

[Théière]

That's ok ErnieY, glad to hear that, its not the clarity its the tint.

[Suandpete]

Ours is going to be 8 years old this summer and up to now there has been no deterioration of terracing or anything obvious to us.  We changed the filtering medium to zeolite a couple of years ago and it has been even better than it was before (and we thought it was good then)- no greyish tint at all.

[AnOther]

[quote user="teapot"]That's ok ErnieY, glad to hear that, its not the clarity its the tint.[/quote]None of that either, crystal clear means exactly that [;-)]

[Suze01]

Yes, I use sel en pastilles pour adouisseurs (sp?) in my pool (and water softener).

The other week I bought 2 x 25kg bags from Hydrosud at a cost of just under 21€ (what a rip off!).  I bought the same stuff in a different bag from Auchan for 5.90€ a 25kg sack, not far off half the price.

Oh, BTW my pool is absolutely crystal clear and has been all winter too, and with no tint [;-)]  [:D]  [:P]

[JohnRoss]

Like others we use the water softener salt which seems to work ok. I have noticed a few small rust coloured stains near the steps end of our pool and wonder if there is iron contamination of some of the salt or if stuff is being walked into the pool. The end affected is near the small road down which many tractors pass and I wonder if they eject small particles of metal from their exhausts. The video was interesting but I suspect that Texas may get less rain than we do which must wash off the slabs around the pool. We have no signs of damage like the stone shown on the video but then we don't splash about like the kids shown so the water stays in the pool.................................................................JR

[chem geek]

Most people who have saltwater chlorine generator (SWG) pools love them and have no problems, but some do.  [url=http://thepoolbiz.blogspot.com/]This blog[/url] has a biased view against salt systems, but it does document the kinds of problems that can occur.  It may be that the reason for more problems in some areas (as JohnRoss points out), especially Texas and Arizona in the U.S., is the use of absorbant hardscape materials such as limestone (and some flagstone) as well as hot dry summers with rapid evaporation.  In other areas, such as Florida, there are summer rains that would wash away (dilute) any splashed-out salt that would otherwise concentrate into some types of stone.

Virtually all of the problems associated with SWG pools can be mitigated.  One can use less absorbant hardscape materials or can seal their natural stone (or even cement; we seal our simulated flagstone that is cement every year even though we don't have an SWG pool).  If one has an aluminum header for a vanishing automatic pool cover, then one can use a sacrificial magnesium anode to protect it (or a zinc anode to protect stainless steel and copper).  One can rinse patio furniture or diving board bases periodically to prevent salt build-up.  One can use (a small amount of) Cyanuric Acid (CYA) in indoor pools to reduce corrosion rates.  One can use curpo-nickel or titanium heat exchangers in their gas heaters or heat pumps instead of copper.

Non-SWG pools don't use plain steel or zinc because of the corrosive nature of chlorine.  In a similar manner, increasing the conductivity of the water by adding extra salt requires some ramping up of the types of materials used, especially if they are already marginal.  Also, the increased chlorides alone may be an issue for stainless steel, aluminum and possibly copper as they interfere with the reformation of a passivity layer (see [url=http://www.epa.gov/triinter/lawsandregs/alloys/alloysreport.pdf]this PDF file[/url], for example).

Richard

[Théière]

It is good to hear that people have salt water pools that are crystal clear. It usual to be contacted by people with problems that have to be sorted out including pictures showing the grey hue. Once the filtration is sorted and chemicals are balanced, I seldom return for a sight seeing trip. 

Chemgeek I seldom see chlorine damage to stainless steel components at swimming pool levels, see it more when OH wipes the stainless fittings in the kitchen with 50/50 bleach as that is sufficient to strip away the passivity layer and cause rusting.

Have a good Easter everyone [:D]

[Suandpete]

Thanks everyone.