Too much salt

[JRM]

I just installed a SWG and Iguess I should have checked my pool's salt level before I added the salt, or I need to double-check the volume of the pool, because I have too much salt in there. The SWG says there's 4000-4200 ppm and Leslie's tested the water and said it's at 5210 ppm (not sure why the difference).

So, the question is; do I need to do anything about this? I assume the level will go down slowly over time due to splashing and backwashing, but we really don't splash or backwash much, so that might take a while. Is there any downside to high salt levels? There's no metal anywhere in the pool; no fittings, no valves, nothing. The pool is in-ground, fiberglass, about 30,000 gallons (I think).

Thanks,
John

 

[Guest]

what brand of SWG and what kind of filter do you have? Also, while you are at it, what is your CYA and TA? (moving right on to the next step to save some time :-D )

 

[iggy]

I just installed a SWG and Iguess I should have checked my pool's salt level before I added the salt, or I need to double-check the volume of the pool, because I have too much salt in there. The SWG says there's 4000-4200 ppm and Leslie's tested the water and said it's at 5210 ppm (not sure why the difference).

So, the question is; do I need to do anything about this? I assume the level will go down slowly over time due to splashing and backwashing, but we really don't splash or backwash much, so that might take a while. Is there any downside to high salt levels? There's no metal anywhere in the pool; no fittings, no valves, nothing. The pool is in-ground, fiberglass, about 30,000 gallons (I think).

Thanks,
John

Welcome. Sorry to hear about your ocean water in your back yard.
The answer your question about how to reduce the salt in the water here it is.
For a 30,000 gallon pool with 5210 ppm and want to reduce to 3200 - 3400 ppm you will need to remove 36 to 40 % of the water and fill it back up with city water. No other way to get the salt out.

Now the questions you will need to answer is what is the sharpe of the pool. max width, Length and depth of the pool?
This way I can help you calculate the gallons.
I suspect with 30,000 is is a large deep pool.
What brand is your chlorine generator?


Hope you get back soon

Iggy in Surprise AZ

If you want you can PM me

 

[JRM]

Hi Waterbear and Iggy, thanks for the replies.

To answer Waterbear's questions:
SWG: Polaris Autoclear Plus
Filter: 36 sqft D.E.
CYA: 100 ppm
TA: 80 ppm

pH is quite low, 7.0, but I was waiting until I decided whether to drain out some water or not before I correct it.

Iggy,
The big question for me is not really how to correct it, but whether or not I need to correct the salt level. If I need to, then I'll drain it, but I hate to see all that water going out and in.

I need to measure the pool more acurately to calculate the correct volume. It's about 36'x18' recatngular with semi-circular ends and long bump-outs on both sides. 8+ feet deep at one end.

Thanks again for the replies,
John

 

[Guest]

You salt level and CYA are both a bit high for this unit. Get your CYA down to about 80 ppm by doing a partial drain and refill and that should bring your salt down low enough to where you don't have to worry about it. For testing your salt level I recommend the AquaChek salt test strip. You can get it from the TFTestkit site if you can't find them locally.

 

[iggy]

To answer Waterbear's questions:
SWG: Polaris Autoclear Plus
Filter: 36 sqft D.E.
CYA: 100 ppm
TA: 80 ppm
pH is quite low, 7.0

Here is the specs for your Chlorine Generator manufacturer
Free Chlorine 1.0 - 3.0 ppm
pH 7.4 - 7.6 ppm
Total Alkalinity 80 - 120 ppm
Calcium Hardness 200 - 400 ppm
Cyanuric Acid (Stabilizer) 80- 100
Salt 3400 ppm

Your readings are ok and your 7.0 ph will rise in a salt pool.
I would suggest to verify your salt level again at the pool store to verify the number. They use electronic tester which is accurate.

If the salt is still as high as they originally said you must replace 40% of the water to get the salt level back to around 3,400 ppm. I just calculated your pool size as 30,000 gal and that is how I determined the water replacement needed to get you back to workable salt range.
DO NOT USE YOUR Chlorine Generator until you reduce the salt level.

Is you have any other questions just ask.
Iggy

 

[JasonLion]

Here is the specs for your Chlorine Generator manufacturer

Umm, actually they say:

Cyanuric Acid (Stabilizer): Per local requirements [Though elsewhere they imply 80 ppm]
Salt: 3000-3500 ppm [This is repeated in several places, but then they say that levels below 2200 won't work]

CYA levels above 80 tend to cause problems, not the least of which is that it is difficult to measure higher levels reliably. When the standard test reads 100 the actual level is sometimes far higher.

Also, in practice electronic testers are just about the least reliable way of measuring salt. Hardly anyone runs proper and frequent calibrations on their electronic testers and without calibration they can drift significantly. AquaChek test strips are currently the most practical way of testing salt levels.

 

[JRM]

Thanks for all the good advice. I have the owner's manual for the pool, so I saw the same thing where they say "CYA per local requirements", but then they have a chart showing how to achieve 80 ppm. Thank goodness I didn't add the CYA before testing it like I did the salt.

That's interesting about CYA being hard to measure over 100 ppm.

Anyway, I'm still curious as to what is the downside of high salt levels?

Also, how accurate are the SWG salt level readings usually? (remember the difference between the pool store test and the reading on my SWG)

Thanks again.
John

(P.S. I'm an engineer, so when I get the time and motivation I'll be measuring my pool foot by foot to calculate the exact volume. With each cubic foot equalling 7.5 gallons (US) it's pretty easy to be a long way off when you're talking and treating in gallons.)

 

[Strannik]

With regards to the higher salt the usual drawbacks are higher corrosion of metal parts, and possible corrosion of surrounding stone (if you have any), depending on materials it's made of.

If your chlorinator is fine to work at that level and you don't have limestone or similar soft stones surrounding your pool, just leave it be.

With regards to accuracy of salt readings, without calibration they would be like a lottery. Can be spot on, or can be way off.

 

[JasonLion]

The risk of corrosion goes up slowly with rising salt levels till about 6000 ppm, where it starts to go up much more quickly. Given the inaccuracies in the tests I recommend staying under 5000 so you are reasonably sure you are actually under 6000.

Having two different kinds of salt tests differ by 20% is not particularly surprising. The best you can hope for without lab equipment is +-10%, which is about what the salt test strips are.