Can I duplicate the feel of a salt chlorine generated pool?

[tigerpilot]

Here's what I'm thinking...
I don't have a problem of lugging jugs of chlorine to my house.
What if I add salt to the pool to get the correct level of salinity.
Then I just add liquid chlorine to the pool and keep the chlorine level stable.
All pool chemistry to be the same as required for a salt chlorine generated pool.
Will I get the "Soft" feel and no burning eyes?
I am thinking the salt is what gives the feel etc.
Ideas please.....
Thanks

[chem geek]

Yes you are correct that it is the higher salt level that gives the better feel. Most people that have tried adding salt to their pools feel they get benefit at around 1000-1500 ppm salt so you don't have to go all the way to 3000 ppm and with lower salt levels you will have less risk of harming stone hardscape or other corrosion issues.

Richard

[Backglass]

Burning eyes isn't cured by salt. If your eyes burn your ph is way off or you have high levels of CC and need to shock to burn it off. All adding salt does for you in a non-SWG pool is give you better "skin feel".

That being said, many people do it and swear by it. Be careful of cheap ladders or nearby stone as it will rust/degrade. You only need a third the salt as a true salt pool to get the "feel". Somewhere around 1000ppm.

[chem geek]

That's true that a burning sensation in the eyes is most likely due to pH out of range (away from 7.5), but a physical "pressure" sensation in the eyes can be due to the salinity of the pool being less than the roughly 9000 ppm salinity of human tears. Water tends to flow through osmosis into the eye and skin (that's why skin gets wrinkled -- it's not dried out, but rather filled with too much fluid) and that creates pressure that can feel uncomfortable.

Of course, too much salt, such as found in the ocean, can hurt the eyes as this causes water to leave the eyes drying them and sometimes stinging.

[Backglass]

That's true that a burning sensation in the eyes is most likely due to pH out of range (away from 7.5), but a physical "pressure" sensation in the eyes can be due to the salinity of the pool being less than the roughly 9000 ppm salinity of human tears. Water tends to flow through osmosis into the eye and skin (that's why skin gets wrinkled -- it's not dried out, but rather filled with too much fluid) and that creates pressure that can feel uncomfortable.

Of course, too much salt, such as found in the ocean, can hurt the eyes as this causes water to leave the eyes drying them and sometimes stinging.

I, of course, bow to your knowledge Chemgeek...you are my "Chlorine Yoda".

There is just such a misconception about chlorine smell, skin & eyes that I didn't want someone to think that salt is the answer to all pool problems. I guess what I was trying to say was that he could add salt and STILL have stinging eyes due to all of the above. Except his skin would feel better while he's crying.

[Salty Dog]

Adding salt to a pool tends to accelerate and existing electrolyses problem in the pool; meaning, copper plumbing and stainless steel tanks will corrode. The way to supress that is the use of zinc balls and feel free to use bonding wire on anything metal to ground it out.

[chem geek]

Adding salt to a pool tends to accelerate and existing electrolyses problem in the pool; meaning, copper plumbing and stainless steel tanks will corrode. The way to supress that is the use of zinc balls and feel free to use bonding wire on anything metal to ground it out.

This is true, but I'm not so sure he needs to worry about that as much at 1000-1500 ppm compared to saltwater chlorine generator (SWG) pools at 3000 ppm salt. It is true that conductivity is roughly proportional to the concentration of salt, but for some corrosion, such as with stainless steel (and aluminum) where the chloride interferes with the reformation of the passivity layer, the corrosion process may be non-linear so lower salt levels may be much safer (and conversely, higher salt levels may be much more damaging). In an SWG pool, zinc-coated (i.e. galvanized) steel corrodes much faster as does some low-grade stainless steel, but high-grade stainless still seems resistant unless the chlorine levels are very high (such as in an indoor pool where CYA is not used). An exception to this is the pitting corrosion that is devastating to stainless steel filters which is why you don't see those anymore.

It should also be kept in mind that plaster/gunite pools that have calcium carbonate saturation and use city water (as opposed to well water) typically add calcium chloride to raise Calcium Hardness (CH) and add sodium bicarbonate to raise Total Alkalinity (TA) and at normal levels these alone combine to create around 250 ppm salt (chloride measured as ppm sodium chloride). Because chlorine converts to chloride when it gets used up, most pools have at least 500 ppm salt and pools that don't get a lot of dilution, such as those with cartridge filters, may have closer to 1000 ppm salt after a couple of years or so.

At any rate, you are correct that attaching a zinc ball or otherwise putting a negative charge on the bonding wire will help reduce corrosion. Just grounding the bonding wire may not help depending on stray voltages that may be present in the ground (though those are usually AC, not DC, but some DC voltages have been found nevertheless). If for some reason there is a current leak to ground (from the SWG cell, for example), then connecting the bonding wire to ground could accelerate the corrosion so the zinc ball connected to the bonding wire is the best approach.

Much more about SWG pools and the effects of salt corrosion may be found at this thread, this web log, and some threads at this link.

Richard

[jburns0211]

I just changed from sand to Zeobrite and also wanted to add salt at about 1000-1500 ppm to get that "soft" feeling. Do you guys see any problems between the salt and the Zeo?

Just wondering,
Janine

[Strannik-au]

Shouldn't be a problem at these salt levels. A lot of people have them together and don't report problems.