Tonight I add salt to my non SWG above ground pool [Archive] - Page 2

ScottS

07-05-2006, 11:38 AM

This may sound strange but I work in a hospital and the main ingredient in IV's for sick people is normal saline which is salt. I know there is some complicated chemistry going on here, but if its ok for us to have a certin amount inside our bodies, whouldn't it be ok to have it outside too, as in our pools?

In a word: yes. :)
and: NO :)

I am not a doctor or a nurse but I had a double lung transplant in 1995. Right now I am on IV antibiotics and found something to be very interesting on this same subject.

The pH of the .9% sodium chloride IV solution ranges from 4.5-7.0 (it states this on the bag). Anything under 7.0 is too acidic for the vinyl and can destroy it. Therefore it is not a safe assumption to state that if we put it into our bodies we can put it into the pool.

I do however like the idea of adding salt to the water. I plan on doing this in a few weeks when I am through with this treatment.

waterbear

07-05-2006, 06:59 PM

If you dissolve sodium chloride in deionized water and test the pH it will be neutral (pH 7) as will the deionized water! Salt will have NO effect on pH. The saline solution you are talking about is probably buffered and NOT pure sodium chloride to compensate for the acid leached from the PVC bag it is packaged in. Most medical saline is packed in PVC bags and then heat sterlized. The PVC leaches some acids into the saline and lowers the pH. This is why the pH is listed as being in the range of 4.5-7.0!

ScottS

07-05-2006, 07:07 PM

The saline solution you are talking about is probably buffered and NOT pure sodium chloride to compensate for the acid leached from the PVC bag it is packaged in. Most medical saline is packed in PVC bags and then heat sterlized. The PVC leaches some acids into the saline and lowers the pH. This is why the pH is listed as being in the range of 4.5-7.0!
This makes sense, thank you! I was wondering why they list a range of #'s for the pH rather than a particular number.

goodfellow

07-05-2006, 10:44 PM

Any thoughts as to what the salt might do over a long frozen winter.

medvampire

07-05-2006, 10:47 PM

Saline in IV bags is buffered to a ph below 7. It is not pure salt and water. There are several reasons for the buffering. We often use saline to piggy back other meds in to the body so we buffer to prevent incompatibility with these drugs. When introducing fluids directly into the blood stream we are usually introducing them in to a vein. The venous red cell is carrying CO2 and slightly acetic itself so we want our IV to be slightly acetic.
Waterbear hit the nail on the head about leaching so we have to give a range not an single value.
There are more reasons but I won’t bore you.
I plan to add salt to my pool as soon I am sure I have my ALK under control.
Steve

Poolsean

07-05-2006, 11:44 PM

Gerri asked...
"I have a 8500 gallon in ground fiberglass pool and I want to add salt.

Here's my question: since I have a problem with iron stains would it be ok to get this kind of salt:
http://www.lowes.com/lowes/lkn?actio...658&lpage=none

The thing I don't understand.. they all say pure salt so how can they be iron fighting, etc. ?"

Gerri, avoid this type of salt. The iron fighting salts have additives that is not good and should not be added. Use water softener salt without any additives and at least 99.5% pure sodium chloride.

Interestingly, I suggested this adding of salt to a non Salt Chlorine Generator pool, oh, say, LAST year? Glad the benefits are being realized.

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.

Answer to the question about above ground pools and tracks, I disagree that you're only dealing with 1000 - 1500 ppm of salt. While this is true with the pool water, splash out water that ends up in the tracks will eventually evaporate, increasing the salinity level as the water evaporates. Realistically, your salt concentration of the water in the tracks can increase way past the 35000 ppm of ocean water.
I recommend that you occasionally wash down the sides of your pool or you will see corrosion over time. Regular rain fall or your sprinkler system hitting the outer pool walls will keep the salt concentration down.

gerri

07-06-2006, 12:56 AM

Thanks Sean. I am glad I asked before getting that type of salt.

Bleach=Chlorine?

07-06-2006, 08:34 AM

haze_1956

07-07-2006, 01:57 PM

Answer to the question about above ground pools and tracks, I disagree that you're only dealing with 1000 - 1500 ppm of salt. While this is true with the pool water, splash out water that ends up in the tracks will eventually evaporate, increasing the salinity level as the water evaporates. Realistically, your salt concentration of the water in the tracks can increase way past the 35000 ppm of ocean water.
I recommend that you occasionally wash down the sides of your pool or you will see corrosion over time. Regular rain fall or your sprinkler system hitting the outer pool walls will keep the salt concentration down.

I was thinking that sealing the bottom of the wall where it fits into the track with some Clear Silcone caulk would also be a good "ounce of prevention". It would keep the salt water penetration to a minimum.

.

ChuckD

07-07-2006, 02:17 PM

Added 160#s of salt to my 22K IG pool this weekend after reading posts and going back and forth on it. Didn't notice any significant difference or taste but I need to add at least another 20-40#s to reach 1000ppm. I didn't feel dried out after swimming all weekend but I do not know whether that is the salt or just my body getting used to the pool. Dumping and mixing the salt was fun though!!

I also have a 22K gallon pool and added double yours, 4x80# bags of 99.8% pure NaCl. I say go for it! I don't know what my salinity is, I went by Mike's bleachcalc, and talk here of desired numbers around 1200 - 1500 (and assumed my well water was close to 0).

I can occassionally, very slightly, taste salt. But normally not. I notice the water feels...different. I almost want to decribe it as slightly more viscous, but I know that's not possible. It's probably the 'softness' others describe. I also notice the water's easier on your eyes and contacts (if you wear yours swimming like I do). I can come up from underwater and instantly see clearly without the usual multiple blinking I must do.

Like I said, I added 4 -80 lb. bags. Just opened them and dumped them down the steps and my 3 year old and I had fun making underwater snowstorms. And in 15 minutes it was gone.

C.

Rangeball

07-07-2006, 02:41 PM

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

07-07-2006, 06:50 PM

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

07-07-2006, 08:36 PM

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

07-07-2006, 08:47 PM

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

07-09-2006, 07:59 PM

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

07-09-2006, 10:18 PM

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

07-09-2006, 10:25 PM

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

The Raddish

07-09-2006, 10:27 PM

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

07-10-2006, 12:46 AM

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 :eek: then removed it quickly!

Poolsean

07-10-2006, 01:13 AM

"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.

cygnusecks

07-10-2006, 08:29 AM

FYI I dumped about 5 lbs into my skimmer, to see how fast it dissolved. It didn't dissolve all that fast (about 5 minutes) and I did not want to sit out there for a hour watching salt dissolve. I said "screw it" and filled the *entire* skimmer with salt, it probably held about 20 lbs. It was so full that salt was coming out of the skimmer :-) I was sure I would starve the pump but it just took more water from the main drain. anyway that meant I could dump in half a bag, go inside, and 10-20 mins later come back out and do it again. Much less work.

gonefishin

07-10-2006, 09:01 AM

I used course solar salt, which was a course flake. It was much smaller (and easier to dissolve) than the pellets. I dumped one 40lb bag at a time in...about 2 foot from the discharge. Then I just aimed the discharge down on top of the salt and almost all of it mixed up in ten minutes or so.

dan

Rangeball

07-10-2006, 09:56 AM

csevel

07-11-2006, 12:08 PM

The two bags only took about 20 minutes or so to dissolve. I just kicked it around with my feet.

The Raddish

07-12-2006, 10:52 AM

The two bags only took about 20 minutes or so to dissolve. I just kicked it around with my feet.
So what do you think? How does your water feel?

hulla

07-12-2006, 06:14 PM

waterbear

07-12-2006, 06:38 PM

Am I the only moron that can't feel the difference in salinity between 1000 to 3000?

My non-swg pool has a salinity of 1000. When I swam in a swg pool, I am not sure if I could tell the difference.

A whole house water softener however is very noticeable to me and is too slimy.
That is because adding salt to your pool DOES NOT soften the water. In a water softener salt is used to charge the ion exhange resin with sodium. When the water flows through it the resin exhanges the sodium for calcium and magnesium in the water. The resin is then recharged with sodium and the calcium and magnisium are washed out to waste so the process can start over. This is what softens the water. Just adding salt to water adds sodium in addtion to the calcium and magnesium already in the water. It has no softening effect whatsoever. The main advantage of adding salt to the pool is to raise the isoelectic point of the water closer to that of the human body. This makes the water less 'irritating".

sevver

07-12-2006, 06:42 PM

That is because adding salt to your pool DOES NOT soften the water. In a water softener salt is used to charge the ion exhange resin with sodium. When the water flows through it the resin exhanges the sodium for calcium and magnesium in the water. The resin is then recharged with sodium and the calcium and magnisium are washed out to waste so the process can start over. This is what softens the water. Just adding salt to water adds sodium in addtion to the calcium and magnesium already in the water. It has no softening effect whatsoever. The main advantage of adding salt to the pool is to raise the isoelectic point of the water closer to that of the human body. This makes the water less 'irritating".

Would it be possible to soften the water in the pool? Could one rig up a water softener to the pool and let it cycle for a period of time in order to do this? I can only imagine that you would need to replenish the salt alot, but would anything else be necessary?

waterbear

07-12-2006, 07:32 PM

Would it be possible to soften the water in the pool? Could one rig up a water softener to the pool and let it cycle for a period of time in order to do this? I can only imagine that you would need to replenish the salt alot, but would anything else be necessary? It might not be desirable to soften the water in the pool. If you have a plaster pool you NEED the calcium hardness to protect the plaster. Also if you have grouted tilework or a heater you, once again, need some hardness in the water or the water will begin to leach out calcium and other metals from the pool, heat exchanger, etc. There is also some indication (but no conclusive data either way) that calium might be needed in a fiberglass pool to help prevent metal staining and damage to the gelcoat finish. Vinyl pools most likely do not need any calcium in them but the effects of totally soft water on the lines is, as far as I know, an unknown variable. Most fill water does have some calcium hardness to it. Water coming out of a softener might have none.

csevel

07-13-2006, 04:17 PM

I LOVE the feel of the water. Less burning of the eyes. Hair easier to comb out. Slight salt taste...but I'm not into drinking pool water so I don't really care.:p

hulla

07-13-2006, 10:56 PM

That is because adding salt to your pool DOES NOT soften the water. In a water softener salt is used to charge the ion exhange resin with sodium. When the water flows through it the resin exhanges the sodium for calcium and magnesium in the water. The resin is then recharged with sodium and the calcium and magnisium are washed out to waste so the process can start over. This is what softens the water. Just adding salt to water adds sodium in addtion to the calcium and magnesium already in the water. It has no softening effect whatsoever. The main advantage of adding salt to the pool is to raise the isoelectic point of the water closer to that of the human body. This makes the water less 'irritating".

Aha! So soft water doesn't have high salinity. It has low hardness (low calcium and magnesium). I guess now I finally realize why it is called soft water.

GraceByDesign

07-14-2006, 12:25 AM

.................The main advantage of adding salt to the pool is to raise the isoelectic point of the water closer to that of the human body. This makes the water less 'irritating".

Same reason we add bath salts to the bath... while it does not actually soften the water, it makes the water feel good!

Grace

Avid reader of this forum
but alas, no pool... yet!

brent.roberts

07-14-2006, 12:47 AM

I put a few bags in our pool mid - season last year and did not tell the wife I had done it. The very first time she went in she commented on how nice the water felt.

This summer we topped up the salt to 2800 ppm and put in the SWG system.

The only negative we've seen so far is that water that gets on top of the *&^%%$$ solar cover and evaporates, leaves a bit of white powered. A few minutes of hosing or a rainfall clears it.

Even at the levels this year that are much higher than we had last year, I still prefer it to straight fresh water.

cheshamjim

07-24-2006, 04:17 PM

I want to do this because my wife has been complaining that her skin feels dry since I have started using BBB. Because I have >120 ppm CYA, I maintain a high chlorine level following the Best Guess chart.

Before adding salt, I wanted to know what my starting point was, so I bought the Taylor Salt Water Test Kit (K-1766). It shows that my water is already at 1,000 ppm salt content. That seemed high, so I called them. They confirmed that the kit was O.K. (the test sample didn't act like I thought it should when adding the reagents) and said that since I have been adding so much chlorine it was probable that the chlorine was the sorce of my salt. Incidentally, I was very impressed by Taylor's telephone support. I talked with a very compentent individual and experienced no waiting.

Anyway, after reading Poolsean's post (#56), I'm going to shoot for 3,000 ppm in my non-SWG pool. Can't wait to be a hero to my wife.

DavidD

07-24-2006, 04:42 PM

(the test sample didn't act like I thought it should when adding the reagents)

Can you say Bloody Mary? :eek: That's the first thing that came to my mind after I did the first test. My salt was around 800 ppm when I tested before adding salt and I've used mainly bleach for a few years. I'm now down to around 3200 ppm (from 3400 ppm) and love it. The kids, and a few other adults say they can taste it slightly but I only get a hint after first jumping in.

Good luck and make a fun time of it spreading the crystals/pellets around.

Dave

P.S-If you have a vinyl pool, I'd recommend the pellets as there are no sharp corners.

cheshamjim

07-24-2006, 05:58 PM

"Can you say Bloody Mary? :eek: That's the first thing that came to my mind after I did the first test."

My test sample looked more like like cream of tomato soup ...

Watermom

07-24-2006, 10:29 PM

medvampire

07-24-2006, 11:46 PM

Watermom
I started on in the China Shop (http://www.poolforum.com/pf2/showthread.php?t=4361). If you want to lock this thread.
Steve

The Raddish

07-25-2006, 10:48 AM

Question - I have long since stopped reading this thread since it is so long. Is it still on topic and productive? It is getting ridiculously long. How about if we stop this one and lock it and start a new thread if there is a need. This one is way longer than we like threads to be. I'll wait a day or two for loose ends to be wrapped up in this thread.

Thanks.
I think that this may be one instance where the long thread is actually not a bad idea. It is still on topic and a wealth of information. There is another thread about this in the China Shop though, so I guess it's up to the mods if you want to keep this one around.

There are still discussions here with questions being asked and answered, so closing it might cut those discussions short.

amyinraleigh

07-25-2006, 12:13 PM

I thought this was already closed and was bummed because I found it very interesting and was hoping to learn more! I had a question and posted it in the other thread that was started as a continuation of this one, but I'd like to repeat it here in case this thread has any followers who aren't reading the other.

I would love to add salt to my pool and am wondering if anyone knows of any reasons it shouldn't be added to an Intex inflatable ring pool.

Thanks! Amy

The Raddish

07-25-2006, 01:16 PM

I can think of no reasons not to add salt to your Intex pool, especially at the low levels that we have been discussing in this thread. :)

matt4x4

07-25-2006, 02:44 PM

Well, I have to try this, I understand that most concerns lie with corrosion, especially the bottom track, let me assure you that the NaCl levels in that track will NEVER reach a high amount such as 35000ppm where it may start to cause a problem unless your pool sits in the middle of the Sahara desert, sure, over the course of the weekend, it may build up a little bit, but the first rain storm will wash 90 % of that salt away.
I won't even worry about any of that since my pool is composed entirely of resin except for the wall and that's so coated you could probably immerse it in 999999 ppm salt and still not have much of an effect on it. As I understand it, most want to get to 1200- 1500 ppm salt, in this case, I'm looking at 250-300lbs of salt which is nuts, so I will be doing this over a loooong period of time.
Oh, also, WRT corrosion, I think everyone who is so concerned should probably be more worried about the alkalinity in the soil that their pool sits on since it will likely be the leading cause of the bottom rail rotting out.