Salt level keeps rising, help!

[thedeadliving5]

My pool was built in April of this year and after 30 days, the PB poured in 7 bags of salt. I can't remember the initial salt levels, but by mid May, I could really taste the salt in the pool. My Screenlogic was reporting it at 4350 which was high so I had the PB come out and drain some of the water assuming they put in too much salt. They got the salt level down to 4000 and said that should be sufficient and as we use the pool more it will gradually go down due to splashout. Well here I am a month later and the salt level was up to 4200 so I went ahead and drained a little over 6 inches and filled it backup with the hose. I am currently maintaining 3800 which is much better, but my question is what could make it keep climbing? My specs are below and the only thing I put in the pool is chlorine and acid.

Note: I thought it might have been that my outside spigot which the auto-leveler is connected to was connected to my water softener, but realized that didn't make any sense because I used that same spigot to refill the pool so the salt would not have dropped, or am I missing something? I believe I read on here somewhere that muriatic acid could increase salinity, is that correct? I have been going through acid like water since initial startup. Any help/clarification would be appreciated, thanks!


Pool Specs:
Freeform
10,700 gallons
Pebble Sheen (Aqua Blue)
InFloor cleaner (PV3)
Paramount Clear O3
Intellichem (only controlling acid, ORP sensor is worthless with SWG)
Intellichlor IC40, controlled through EasyTouch 4, currenty set at 15%
Intelliflow VS
-runs on high speed/cleaning, 12:00am -5:00am (2750 RPM)
-runs in Pool mode, 7:00am - 11:55pm (1900RPM)
-Waterfall (not on very often) -runs at 2500 RPM


Current Stats:
PH: 7.48 (set level of 7.5)
TA: 90
CYA: 80
TH: 250
FC: 6.0 (set level of 6)
Salt: 3800

 

[jblizzle]

SWG systems only do a rough estimate of the salt level (based on temperature and water conductivity) ... they are only good to +/- 400ppm or so. So, I think you might be worried over nothing.

 

[thedeadliving5]

SWG systems only do a rough estimate of the salt level (based on temperature and water conductivity) ... they are only good to +/- 400ppm or so. So, I think you might be worried over nothing.

That would be awesome, hopefully that's all it is. I have a testing kit that came with the pool which does well for most, but I have yet to find a good salt test, any recommendations?

Thanks for the reply!

 

[YippeeSkippy]

How are you obtaining this salt level? Is it from the SWG itself or an independent salt test?

My SWG *thinks* I have high salt but I use Taylor's K-1766 salt test and know its not. Too lazy to figure out how to re calibrate the SWG, and it continues to make chlorine so Skippy and I ignore it. If the SWG is happy, I'm happy!

Also some folks are just more sensitive to the salt taste than others.

 

[jblizzle]

I agree with the Taylor salt test above.

FYI, from day 1, my Hayward SWG has read about 600-800ppm lower than my Taylor test. As long as that trend holds, I am not too concerned.

 

[thedeadliving5]

Thanks for all the replies guys, I went ahead and ordered my own Taylor's K-1766 salt test from TFTestkits.net.

 

[mguzzy]

I will concur with Mr Blizzle.. My chlorine system salt readings do no match my tests. testing always showed a lower concentration of salt than the SWG equipment did. So if I put in the amount of salt the tests called for my SWG would be complaining of high salt. Soo I always go by what the equipment wants.. I assume its been calibrated at the factory to some standard. Now I just got a new cell (first one lasted almost 10yrs).. I'm curious to see if those readings are hold true with the new cell.

 

[needsajet]

The practical answer is all covered above. Just to cover the other questions, muriatic acid will not change the salt level. You mentioned you only add chlorine and MA. If you add chlorinating liquid, you're adding 15 PPM salt for each gallon of 10% bleach, so not a big deal there, unless you did a 40 gallon SLAM or something.

 

[thedeadliving5]

The only chlorine going into the pool is from the SWG so we are good there, as for the acid adding salt, I am glad that was debunked because I go through acid pretty quickly.

 

[tonyo]

Note: I thought it might have been that my outside spigot which the auto-leveler is connected to was connected to my water softener, but realized that didn't make any sense because I used that same spigot to refill the pool so the salt would not have dropped, or am I missing something?

You are missing the evaporation.

If the splash-out rate is sufficiently less than the evaporation rate, then gradually adding saline water to the pool, even if it's less saline than the pool itself, will increase the pool's salinity. The pool's salinity will then drop again with a partial pump-out and replacement with less saline water.

 

[mguzzy]

...Note: I thought it might have been that my outside spigot which the auto-leveler is connected to was connected to my water softener, but realized that didn't make any sense because I used that same spigot to refill the pool so the salt would not have dropped, or am I missing something?...

Tonyo's post made think of something. First off adding saline water to a pool will raise the salinity only if the concentration of the added water is higher.. otherwise it dilutes it. The effect of evaporation by itself 'usually' cancels itself out. As water (non saline) evaporates from the pool, the pool's salinity goes up and its usually replaced with non saline water from your refill source to return the pool to its same salinity. BUT in your pool you think you may be replacing the evaporated, non saline, water with water from your tap that has some salinity. Hence the there is a net infow of salt.

To test that theory I think you need to test the salinity level of your tap water. If it is more saline than what is getting evaporated that would explain a net increase in the salinity. I would be interested in seeing if the math bears that out.

 

[thedeadliving5]

It looks like my Taylor kit was delivered today so I will be testing and comparing the water from my spigot and from my sink in the house to be sure. Any guidelines on how much water I will need to test from each source to get the most accurate results? Also if this is the case and my spigot is delivering softened water which will eventually increase the salinity, what is my best option?

1. Have a plumber change the spigot to another water source before my softener?
2. Turn off the auto-fill during the day and only turn it on at night when I have bypassed the softener?
3. Drain a % of the water each month?
4. Swim more often which would create more splash out and keep evaporation minimal? This one sounds like the most fun

This sucks, if only my PB would have asked if I had a Softener in my home prior to connecting the auto-fil to that spigot, sad times.

 

[jblizzle]

Forget about the salt ... I wish I could top off with softened water to keep the CH from rising so fast. The high CH is more likely to be a problem than the salt.

I will be curious to see how your numbers compare with the different water sources. I would certainly test the salt and the CH.
For the CH test use 25ml of water so each drop becomes 10ppm (instead of 25ppm if you used 10ml).
For the salt, the normal test is 10ml of water for each drop being 200ppm ... might try 20ml of water so each drop is 100ppm, although that still may not be a small enough division. There might be a 44ml line on the tube, so each drop is 45.5ppm.

 

[mguzzy]

]... what is my best option?

1. Have a plumber change the spigot to another water source before my softener?
2. Turn off the auto-fill during the day and only turn it on at night when I have bypassed the softener?
3. Drain a % of the water each month?
4. Swim more often which would create more splash out and keep evaporation minimal? This one sounds like the most fun
....

5. Hire a bunch of neighborhood kids to splash water out of your pool each day
6. Run a hose from you neighbor's house to your autofill.. assuming your neighbor does not have a similar water softener
7. Put a dome over your pool so it becomes a closed system, no evaporation/no splash, no need for additional water-kind of like the plastic covers your mom put over the couch
8. Turn the pool into a fusion experiment.. you have discovered an new miracle source of salt. sell tickets, make a fortune
9. Put in a line that pulls the autofill before your softener system. Just curious, are your sprinklers and outside hosebibs flowing softened water?

 

[thedeadliving5]

I love number 6
As for number 9, From what I can tell the spigot in my front yard is not receiving soft water because it is split off prior to the softener (outside the house). That spigot has a shutoff valve that connects to another pipe that runs through to my sprinkler system in the back yard.

 

[bdavis466]

There have been a couple things stated that are not correct.

Muriatic acid absolutely increases the chloride content in the water. One gallon of full strength acid is the near equivalent of adding 5 pounds of salt. In your 10,700 gallon pool this is just over 50pmm per gallon of acid.

Most municipal water supplies have some measurable levels of salt. As water evaporates, the solids in it are left behind. Since the make up water has salt in it, this will contribute to a salinity rise as well (albeit a minor impact).

Take a water sample from your water softener and compare that with your untreated water. Softened water is usually very high in salt.

I have found that as long as the water temperature is above 70 degrees, the SWG salinity reading is very near the results of the Taylor test.

My salt level rises by 1200-1500 ppm per year and is primally caused by acid demand. Your best bet to reduce acid consumption is to lower the TA and maintain a pH in the 7.8 range.

 

[thedeadliving5]

I was really hoping it was not the acid because I go through it quickly. I went through an entire gallon in less than a week to maintain a level of 7.5 which is the set point on my intellichem. I did notice that my ozonator is broken/not receiving power so the venturi loop which was injecting the ozone is simply sucking air into the pool. If I am not mistaken, aeration raises ph as well so hopefully a new/fixed ozonator will help a little.

Right now my TA is at 90 and my ph set point is 7.5 which is easily changed to 7.8, but the TA, how low we talking?

 

[bdavis466]

50-60 on the TA would be great.

You are correct about aeration raising the pH and this increases exponentially at lower pH and higher TA levels.

Your pH at 7.5 and TA at 90 has 9.3 times the carbon dioxide content of the air which will outgas in attempts to form an equilibrium.

A pH of 7.8 and a TA of 50 is 2.4 times greater which is much closer to being stable and still provide for a relatively balanced CSI. PH rise from aeration will be minimal at this level.

 

[thedeadliving5]

What is the best method to reduce TA levels without affecting ph levels?

 

[YippeeSkippy]

I don't know of any other way except using muriatic acid to lower both the TA and the pH, but then using aeration to raise the pH again. Its a process and it works very well.