Threshold for salt taste and potential damage to plants

TomU

LifeTime Supporter
Apr 22, 2007
93
Wyoming, Michigan
#1
I was doing a little digging on the web and I've noticed a discrepancy between the threshold given for tasting salt. Most of what I've read here and on the SWG manufacturer's sites list 4000 to 6000 ppm as being the point at which most people can taste salt. Earlier this year I added enough softener salt to my pool to bring the level up to 3200 ppm (as measured by the Aquacheck strips). The first time I used it after adding the salt I immediately noticed the salt taste. Everyone else who has used the pool has also commented on being able to taste the salt. I was kind of surprised since I assumed I was below the threshold of taste. As of today, the salt level has dropped down to 2400 ppm (due to backwash, splash out, etc.). Even at this level the salt taste is very obvious.

I recently came across this Australian site: http://www.sa.waterwatch.org.au/sw_salinity.htm. What was really interesting was that it clams water "would start to taste very salty" somewhere between 480 and 1500 ppm. This is significantly below the thresholds I've seen stated other places, but would seem to better correlate with what I'm seeing in my own pool.

The other part that was interesting was the comment that "Some plants such as peas, apricots and grapes cannot be grown with water over 1500uS/cm". Based on the ranges shown, I'm interpolating this is approximately 1000 ppm. This could be significant if you live in an area where your backwash water is not being pumped into the sewer system. Yes, I know some people have backwashed their water for years near plants, trees, etc. with no issues. I'm not saying its a problem, I just found it interesting.

Tom
 

The Mermaid Queen

TFP Expert
LifeTime Supporter
Mar 28, 2007
2,522
Northern KY
#2
I can taste a difference in the water in a SWG pool vs a non-SWG, but the taste is not actually salty to me, just different. Don't know what the salt levels were tho...
 

Rangeball

Well-known member
May 25, 2007
785
#3
I have 1800 ppm salt in my non SWG pool and no one has commented on a salty taste. Of course they don't know it's in there either :)

I can't taste the salt though, and the water feels fantastic.
 

JasonLion

TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
37,879
Silver Spring, MD
#4
Keep in mind that different people start tasting salt at noticably different levels. From what I have seen most people can't taste salt below 2000 and most people can taste salt above 3500. But I have no doubt that there are some exceptional indiviudals that are well outside that range (in both directions).
 

KurtV

LifeTime Supporter
Mar 29, 2007
270
SE Louisiana
#6
I read somewhere recently (might have been on The Pool Guy's blog) that some government agency (EPA maybe) declared the taste threshhold to be 250 ppm. As Jason said, though, everyone perceives the salt at a different level.

I can definitely taste the salt in my water, which is probably somewhere between 1000 and 2000 ppm (haven't tested it since adding the salt a year or so ago). The taste isn't at all objectionable to me and wasn't even when it was 2500-3000 ppm.
 
G

Guest

#7
I have about 3300ppm salt in my pool and 50 ppm borates and I have a lot of family and friends that come over to use the pool. NO ONE has ever commented on the water tasting salty, unless I tell them it's a salt pool and then they say that they can taste a tiny bit of salt. Almost seems like power of suggestion. They do comment all the time on how nice the water feels, however.
 

sredish

LifeTime Supporter
Jul 3, 2007
207
North of Dallas
#8
3200ppm in mine currently. I can't taste the salt, but I could when it was at 3500 when the swg was first installed. Now, my wife says the pool tastes like the ocean we just vacationed at last week.... I say she's out of her mind.... that stuff was salty!!
 

NWMNMom

TFP Expert
LifeTime Supporter
Apr 8, 2007
1,582
Waaay NW MN
#9
We could taste the salt last year and we definitely taste it now that the levels are up around 2000-2500. Its not a bad thing, just different.
 

gonefishin

LifeTime Supporter
Apr 5, 2007
413
Joliet, Il.
#10
I could taste the salt in my non-salt water pool. It's at 1,100ppm. I've got some extra salt test strips...I'll have the wife mix up some glasses with various levels of salt and some without salt at all and see what I could taste...or not ;)



dan
 

NWMNMom

TFP Expert
LifeTime Supporter
Apr 8, 2007
1,582
Waaay NW MN
#11
There ya go! Thats the spirit. I personally do not add salt to any food I cook or eat, but do know almost all processed food is full of sodium. Anyway, I think thats probably why I feel kind of sensitive to salt, because I am not used to a lot of salty foods that some people are. Do you think?
 

chem geek

TFP Expert
LifeTime Supporter
Mar 28, 2007
12,082
San Rafael, CA USA
#12
There is a HUGE variation in the number of taste buds people have -- I've seen factors of 100 being mentioned for the difference, but that might have been bogus info (and may relate to the variation in concentration needed to detect tasting some substances, rather than in the number of taste buds themselves). This link contains some interesting info including "supertasters" who are more sensitive tasters -- more women than men, by the way. This link has some more info about taste buds (less technical) and the 0.01 M threshold they list for salt is 584 ppm but the threshold had only one digit so was likely very approximate. So I would expect the sensitivity level for taste to most any substance to have wide variation among individuals. One might also expect that frequent exposure to higher levels of a substance might train the brain to be less sensitive to it and to have a harder time discerning low levels, but that's speculation on my part (but is consistent with NWMNMom's point).
 

poolio

Well-known member
Jun 23, 2007
58
#15
there is a difference between tasting the salt and just the water tasting different. What most of you guys are tasting is the water being different not necessarily the salt. Dont forget everytime someone pees in your pool that adds salt to it too.
 

gonefishin

LifeTime Supporter
Apr 5, 2007
413
Joliet, Il.
#16
poolio said:
there is a difference between tasting the salt and just the water tasting different. What most of you guys are tasting is the water being different not necessarily the salt. Dont forget everytime someone pees in your pool that adds salt to it too.

I really think that 1,100ppm is beyond my point of just noticeable differences. To me...I'm not surprised at all that I can taste salt, because I added a good amount of it to my water.

dan
 

Pool_Mike

Active member
Apr 3, 2007
41
Central Texas
#17
waterbear said:
I have about 3300ppm salt in my pool and 50 ppm borates and I have a lot of family and friends that come over to use the pool. NO ONE has ever commented on the water tasting salty, unless I tell them it's a salt pool and then they say that they can taste a tiny bit of salt. Almost seems like power of suggestion. They do comment all the time on how nice the water feels, however.
Ditto. I honestly only taste it when I dive in 1st time. After that, no more salt taste. Plus love the way my skin feels when I dry off w/ a towel. Felt like I took a smooth clean shower ;)