suggestions on chem levels

[waterbear]

Are there any risks or downsides to adding salt to a pool that's not a 'true' salt water pool? Corrosion?

Corrosion is alway a risk in any pool, salt or not. (and any pool that uses chlorine will have salt in it. It's what forms in the water when the chlorine is used up sanitizing and oxidizing stuff!)

That being said, there is pool equipment out there that is not compatible with salt levels found in SWG pools (3000 ppm or higher), mainly steel frame AGPs, older heaters with copper heat exchangers, some ladders and a lot of the cheap stainless steel screws that manufacturers include with light niches and ladder mounts to save a few pennies. Most newer pool equipment had no problems with salt.

Also, it seems that the natural rock used in some pool construction in certain parts of the country (parts of Texas seem to have the most problems) are susceptible to damage from salt.
IMHO, this is because materials are being used in pool construction that should not be used. Period. I live on the coast (actually less than a block from the Atlantic and about a quarter block from the Intercoastal) so construction here (and not just pool construction) is designed to be resistant to salt effects.
This is why I say it is not the salt that is causing the damage but the selection of unsuitable building materials.

[sturev]

Thanks Evan! (like the name BTW )

[sturev]

That being said, there is pool equipment out there that is not compatible with salt levels found in SWG pools (3000 ppm or higher), mainly steel frame AGPs, older heaters with copper heat exchangers

Humm... I have a heater with a copper heat exchanger...http://www.haywardnet.com/abovegroun...oductID=81#six
I guess this means I shouldn't up my salt levels...? I wonder if I stayed on the lower end of the scale if it would be ok? (1000 ppm)

[chem geek]

It's a spectrum of risk. A copper heat exchanger is more susceptible to corrosion than a cupro-nickel alloy or a titanium heat exchanger, but it doesn't mean that it will definitely corrode too quickly at SWG salt levels (typically 3000 ppm). There is no question that it will corrode faster, but as to whether this will be a problem before the heater would fail for other reasons, that is not certain.

Given how many people have converted to SWG pools, I think the copper heat exchangers aren't the biggest problem -- at least that isn't the most common complaint. The other items waterbear mentioned seem to be the more common issues -- namely, cheap stainless steel or regular steel (or even zinc) used in screws and some softer stones used in parts of the country that also don't have regular summer rains. "Vanishing" aluminum headers on automatic covers and aluminum tracks are also a problem, but are usually mitigated by using a sacrificial anode. In fact, you could at least partially protect all the metal in your pool by attaching a sacrificial anode (usually zinc; sometimes magnesium) buried in moist soil to the bonding wire.

[thilbert]

Sorry, didn't mean to do a drive by and not answer your questions regarding salt. Waterbear nailed it. You could do a google search for pool calculator and find a nifty online tool that will tell you the effects of adding various amount of "stuff" to your pool, including salt.

Waterbear, thanks for clearing up the "softening" issue. Not being a chemist I was attempting to explain my own experiences with salt and "soft" was the only thing my feeble mind could come up with.