Tonight I add salt to my non SWG above ground pool

[Rangeball]

Question to everyone though....why only add salt to 1000 ppm? The higher the salinity, the closer to your bodies salinity level, thus the more comfortable it will be.

Sean, the theory was/is that SWG manufacturers usually recommend about 3000 ppm. Some of that salt is tied up when converted to chlorine, leaving a smaller part as true salinity. Therefore, putting only the amount in that would match what is present in an SWG pool minus the converted amount would most closely replicate the feel and ability to taste salt in SWG pools.

Please feel free to shoot this full of holes

[MassAttack]

Interesting thread.

Does anyone know how high the salt content needs to be to keep the water freezing? Are there any real pros or cons on whether or not your pool water freezes during the winter? I am in New England where it gets pretty cold in January...

[smallpooldad]

The pool is 9000 gal gunite in Hawaii, at an elevation of 1000ft so nowhere near the ocean. The salt measured 400 ppm before putting in additional salt to raise it to it to 1400 ppm using Ben's calculator. Now several weeks later a Taylor Saltwater kit is showing 3000 ppm (15 drops)? But TDS is registering 1800 ppm when it was 560 ppm before. This is weird!

The water feels great, no stinging of eyes, and virtually no salty taste.

But where did this additional salt come from or is the reading or kit bad? Is it bad for the pool to be at 3000ppm?

Use Wal-Mart's liquid bleach, muriatic acid, baking soda, the blue stuff, and Algaecide 60. Have always had an iron problem from flying red-dirt (ferric oxide AKA rust) but this is under control.

Temp 80 F
pH 7.4
Alk 100
Cl 6.0
Hardness 375
CYA 50
Salt 3000?
TDS 1800
Pool Crystal Clear

Help!

[NWMNMom]

Well, I just added 120# of solar salt a few hours ago. The taste is very slightly salty we think, but maybe just our imagination? Anyway, DH came home from a hot, dusty afternoon in the field on a broken down tractor with no a/c - jumped in and immediately said, "What did you do to the pool?" Summary: I big thumbs up! (I opened my eyes underwater with no stinging, my hair is NICE afterwards)

[csevel]

I added 100# of 99.8% pure salt to my 8500 gal. pool yesterday. Don't have a test kit to measure the salinity but I noticed the difference in the water immediately. The pool definitely has a slight salt taste but not at all bothersome. I liked the way my skin and hair felt afterwards and think I'll enjoy opening my eyes underwater without the stinging.

[NWMNMom]

Does anyone know how high the salt content needs to be to keep the water freezing? Are there any real pros or cons on whether or not your pool water freezes during the winter? I am in New England where it gets pretty cold in January...

This is a good question... Does anyone know the answer to this? My mother in law also brougt it up when we told her we put salt in the pool.....

[bryjen]

How long does it take for the salt to disolve. The salt pellets look pretty big.

[The Raddish]

At a guess, I'd say we'd have to increase the salinity much beyond what the 1000 - 2000ppm most of us have been targeting.

I remember from college physics class that the absolute minimum freezing point of salt water is around -20° C. This is only at the point of maximum salinity in which the water can not possibly dissolve any more salt, which is somewhere around 20% salt. These are guesstimate numbers vaguely remembered through the fog of college labs and tests. I don't remember the exact values, but I'm sure I'm close.

Otherwise, any increase in the salinity of water will drop the freezing point by some amount, but I'm not sure if it is on a linear scale or not. Those of us who have added salt to our water will detect that our water will not freeze at 0°C, but maybe at -2°C or maybe a little warmer or colder. In other words, we haven't added enough water to truly make a difference in the freezing point, but we have lowered it somewhat, even if minimally.

[gerri]

How long does it take for the salt to disolve. The salt pellets look pretty big.

About 15-20 minutes per 40 pound bag. It can get sharp as it dissolves too.. I have a cut on my toe and several on my hands from doing it yesterday. My toddler thought it was ice and put a piece in his mouth then removed it quickly!

[Poolsean]

"the theory was/is that SWG manufacturers usually recommend about 3000 ppm. Some of that salt is tied up when converted to chlorine, leaving a smaller part as true salinity. Therefore, putting only the amount in that would match what is present in an SWG pool minus the converted amount would most closely replicate the feel and ability to taste salt in SWG pools."
Very little salt is consumed in the process of producing chlorine. The higher salt level creates a conductivity in the water that is needed to pass the electricity within the cell.

"Does anyone know how high the salt content needs to be to keep the water freezing? Are there any real pros or cons on whether or not your pool water freezes during the winter? I am in New England where it gets pretty cold in January..."
At 3000 ppm, the water will still freeze but instead of 32 degrees, it will freeze at about 30.7 degrees. No significant difference.

"The pool is 9000 gal gunite in Hawaii, at an elevation of 1000ft so nowhere near the ocean. The salt measured 400 ppm before putting in additional salt to raise it to it to 1400 ppm using Ben's calculator. Now several weeks later a Taylor Saltwater kit is showing 3000 ppm (15 drops)? But TDS is registering 1800 ppm when it was 560 ppm before. This is weird!"
hmmm, bad reagents or incorrect testing procedure. It's impossible for the TDS to be lower than the salinity. Salinity adds to the TDS reading. There is nothing wrong with maintaining 3000 ppm of salt. When you get into the higher salinity levels of 6000 or greater, it can cause corrosion to metals in the water.