How To Reduce the Salt Level In Your Pool

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You've just converted over to a salt water pool and discovered that your resulting salt level is too high. You were targeting for 3500 ppm and ended up with over 4000 ppm. How could this happen? The most common answer is you overestimated the size of your pool. Instead of having 13,000 gallons you have 10,000. Now you have too much salt in your water. How many pounds of salt are you over and how do you get that out of the pool water?

Step by Step

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Step 1

The only way to reduce the salt level in your pool is to dilute it. And if your pool is full that means you are going to have to drain your pool down to a level that you can add fresh water to. You cannot wait for the water to evaporate. That does nothing to reduce the salt level. In fact, when the water evaporates, the salt still remains in the pool and your salt level actually goes up. So the question now is, "How much do you have to drain to make room for fresh water?".

Step 2

Salt water generators operate between values that range from 3000 ppm to 4000 ppm. We are assuming that you have a salt water generator that operates at 3500 and so you were adding salt to reach a salt level of 3500 ppm.

Step 3

When you measured your salt level using salt test strip you got a reading of just above 6.5 which equates to 4000 ppm. So you're over by 500 ppm. What's that mean in real numbers and how do you get it out of your pool.

Step 4

To help visualize this we will convert ppm to bags of salt. On the back of the salt bag it states that 1 40# bag of salt will raise the salt level by 480 ppm for a 10,000 gallon pool. So if your pool's salt level is 4000, you have just over 8 bags of salt in your pool (4000/480). To reach 3500 ppm in a 10,000 gallon pool you should have the equivalent of just over 7 bags (3500/480).

Step 5

You have about 8 bags of salt in your pool . You want to extract about 1 bag of salt. To do that you have to you have to drain about 1/8 of your pool water.

Step 6

When you replace that 1/8 of pool water with fresh water, you'll end up with 7 bags of salt or approximately 3500 ppm.

Step 7

So you must dump 1/8 of the pool's water. How many inches of water is that? First determine the average depth of your pool. If the shallow end is 3' and the deep end is 6', your average depth is 3' + 6' or 9 ' divided by 2 = 4.5'. This is equal to 54". To determine the number of inches to drain from your pool to dump 1/8 of your pool water, divide the average depth of your pool in inches by 8 (54 / 8 = 6.75 or approximately 7"). Bottomline - to reduce your salt water level from 4000 to 3500, you must drain out 7" of salt water and replace it with 7" of fresh water. The basic formulas you need to get to this number are restated below. They will work for any pool size.

Step 8

A: % OF SALT OVER TARGET PPM = (measured ppm - target ppm) / measured ppm. In our example (4000 - 3500)/ 4000 or 500 / 4000 = 12.5% which is the same as 1/8 discussed above. Note: It is not necessary to convert ppm to bags of salt as done above. That was only done to help visualize the problem. Also note that this formula works for most size pool. We only have to consider the depth , not the width or length.

Step 9

B: AVERAGE DEPTH OF POOL: (Shallow End + Deep End)/2 x 12. In our example, (3' + 6')/2 x 12" = 54".

Step 10

C: NUMBER OF INCHES TO DRAIN: B times A. In our example, 54" x 12.5% = 6.75" (approximately 7")

Comments

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(1 to 40 of 111)

Anonymous  Posted: 7/5/2019 

thanks for this info...found you on a google search. top of results. Good stuff!
 Reply

Anonymous  Posted: 6/9/2019 

my aqua pump is reading 900 ppm and we have put seveal bags of salt in it and it still reads the same and also my cell power light is on
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 Posted: 8/31/2019 

Also make sure you have the right cell size programmed on your generator. I had this issue after the power tripped. It was simple to fix but it would have been a major issue as no chlorine was being generated.
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 Posted: 7/27/2019 

Turn system off and wait a few minutes. When you turn it back on the SCG should read more salt. Be careful, I cover did the salt too ;)
 Reply

 Posted: 7/26/2019 

The membrane most likely has calsification on it. Take it out and soak it in vinegar overnight Rinse and reinstall.
 Reply

InyoPools Product Specialist  Posted: 6/19/2019 

V-Green 1.65 HP Square Flange 48Y Variable Speed Motor - ECM16SQU
 Reply

 Posted: 5/29/2019 

We have a brand new salt water pool. (Above ground) we have put in all recommended chemicals. We even brought a sample of our water to a pool place. The pump keeps saying high salt, but it’s not high...the pool place said it could be a chemistry thing. But it keeps flashing high salt and it puts the system to sleep. We have even tried cleaning all of the parts individually. Please help..... does anyone know what it could be?
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Anonymous  Posted: 8/6/2019 

Furthermore, our reading at the pool place shows salt at 3,068 ppl.... If anything i would say it is low - not high
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Anonymous  Posted: 8/6/2019 

We have the same issue.... Started today I believe... We have had the pool open for a couple of weeks with no additional salt being added and we cover up the pool every night so little evaporation. Pool guy suggested a bag of burnout so I am trying that... Otherwise they don't have a clue... Great..
 Reply

InyoPools Product Specialist  Posted: 8/7/2019 

Have you tried recalibrating the salt system? You may also want to check the control box has the correct cell size listed under its settings; this is a common issue with Hayward salt systems.
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InyoPools Product Specialist  Posted: 5/30/2019 

Have you tried addressing the water chemistry issues the pool place mentioned?
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 Posted: 5/11/2019 

I have a pool that is 24’x 52”. I added 13 bags of salt since the salt level machine read low. Unfortunately there was something wrong with the machine. We replace the salt machine but now it reads at 4210. How many gallon of water do a need to take off to make it at 3500 ppm.
 Reply

InyoPools Product Specialist  Posted: 5/13/2019 

Going by percentages, 3500 ppm is 83% of 4210 ppm. So, you would need to drain around 17 percent of your water.
 Reply

Anonymous  Posted: 5/6/2019 

I have standard 18 x 36 8 ft deepest end 4 ft shallow end . My pool guy came out to work on my pool because it was green. He told me that my salt was just low even though I told him, I had just added 6 bags. He told me I needed 7 bags more long story short my salt level is 6000 how many inches do I need to drain and replace with fresh water. any help is appreciated. Note to self don't listen to professional when you know he is wrong.
 Reply

InyoPools Product Specialist  Posted: 5/7/2019 

It depends on what you desired salt level is. If your current salt level is 6000 ppm, and the desired salt level is 3000 ppm; half the pool would need to be drained. Your average depth is 6 feet; the pool would require 3 feet of water removed
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 Posted: 4/22/2019 

I clean the salt cell every 3 months. It is 3 years old. The salt reading is 200 but when I had it tested at the pool place it was 4500. The chlorine level is 0. Is it safe to assume the cell is bad?
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InyoPools Product Specialist  Posted: 4/23/2019 

That is a good sign that the cell has gone bad. A 3-year lifespan is very common.
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 Posted: 1/24/2019 

My salt cell is turned off all winter due to water temp well below 60 degrees. Throughout the winter months I.pump a lot of rainwater out of the pool, lowering the salt level. Do I need to keep adding salt all winter to keep salt level above 2500 or can I wait until the water temperature rises too bring salt level into range?
 Reply

InyoPools Product Specialist  Posted: 1/24/2019 

Hello TR - I would wait to add salt until you plan on turning on the salt system.
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 Posted: 1/24/2019 

Thank you. That’s what common sense was telling me but sometimes my sense isn’t very common.
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InyoPools Product Specialist  Posted: 1/24/2019 

You're welcome. It never hurts to get some assurance.
 Reply

 Posted: 10/1/2018 

Hello Michelle - Yes, you can set the valve to waste when you drain water.
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 Posted: 10/1/2018 

Do you just set the valve to waste water to drop the salt level or do you have to vacuum?
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InyoPools Product Specialist  Posted: 8/25/2017 

Rk - The only way to reduce your pool's salt level is to drain out some of the water and replace it with fresh water. I'd have a local pool store check your salt level to make sure your reading is accurate.
 Reply

 Posted: 8/24/2017 

Salt level is 3700 now. Can you lower the salinity percentage to decrease salt?
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InyoPools Product Specialist  Posted: 7/20/2017 

Ronnie - I would have to know what Salt Chlorine Generation system you have to help isolate your salt level problem. From the partial readings, it sounds like your SCG is not producing chlorine. Generally, on many systems, when you change the cell, you have to enter the cell type into the control unit otherwise the unit will generate invalid numbers. If you have an Aqua Rite system, here is a link to "Haywards' Aqua Rite Diagnostics Manual". It may help you with general insights.
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InyoPools Product Specialist  Posted: 7/19/2017 

Anonymous (high salt) - I need to know what SCG system you have to help you with HI salt level issue. Sounds like your SCG is not producing any chlorine. Even though the system is new, I'd have the cell checked. Throw in a bag of shock to control the algae while you are getting this resolved.
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Anonymous  Posted: 7/17/2017 

We have a new pool that called for 4 bags and ever since it says high salt even drained half the pool and still high salt. Don't understand. We followed all the instructions. Pool just keeps turning green. Please help
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 Posted: 7/17/2017 

I will begin by saying I love the way you reply to customers with numerous questions, it made me want to trust you. My pool is 14000 gal. After 12 Yrs of used we had to buy a new cell, followed your steps to recalibrate it. Went through all steps to understand all the 9 codes and found out ours doesn't have 9 codes. Its always showing HI. Then I begin pushing the diagnostic button and this is what I get: Code #3 shows 0.00, so we don't know the cell amp. Code #5 indicates -0. Code #7 shows r-1.40 but not sure if is because the cell is T-15. Once I press to continue it goes back to HI and doesn't show any other codes, to my understanding our system has only 7 codes. Is still a bit green after following all the steps, we shocked it, pour murat ice acid, has a new filter, stabilizer, clarifier, you name it and let me know what else to do if I missed something. Thank you.
 Reply

InyoPools Product Specialist  Posted: 7/10/2017 

LENA - I would question the results of the Clorox salt water tester. If you can, take a sample of your pool water into a local pool store. They have more accurate equipment and should test your pool water for free.
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 Posted: 7/8/2017 

Clorox salt water tester showed the salt to high at 7.0. I drained half the water out of my 12000 gallon pool.tested and the test shows the same.That can't be right.At my ropes end grrrr
 Reply

InyoPools Product Specialist  Posted: 7/3/2017 

Anonymous (high salt level) - I would recheck your salt level. If your 53,000-gallon pool has a salt level of 9500 ppm, you would have had to put over 100 40 lb bags of salt into your pool. For a typical operating level of 3500 ppm you should only have about 39 bags in your pool. That would mean you would have to take about 60% of your water out and replace it with fresh water to get your salt level down to 3500 ppm.
 Reply

Anonymous  Posted: 7/2/2017 

My pool is 53,000 gallons and the salt reader reads high in the 9 thousands how much do I need to drain my pool and clear up the water
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InyoPools Product Specialist  Posted: 6/9/2017 

Anonymous (reduce salt) - All you really have to know is the amount of water you have to drain from the pool and the average depth of the pool as stated in steps 8, 9, and 10.
 Reply

Anonymous  Posted: 6/8/2017 

Could you not just take (3500,Target/4000,current)=1/8. Then take 1/8th the gallons of pool water, (800 gallons) X 0.133681(gallons to Cubic Foot) divide by Length then divide by width. This will equal the number Feet to drain. Divide by 12 and you will have the number of inches to drain. The Salt bag is irrelevant.
 Reply

InyoPools Product Specialist  Posted: 5/17/2017 

Chaphouse - You would, of course, have the auto fill off while you are draining the pool, but there's is no reason for not refilling the pool with the autofill unless it is too slow. If you drain below the skimmer and have diverter valves, you can shut off the skimmer and drain from the bottom of the pool to avoid getting air in the system. As for the algae problem, see our blog on "How to Clean a Green Pool". It's simple and works.
 Reply

 Posted: 5/16/2017 

Thank you for all these comments! I found them very helpful!
I have high levels of salt in our pool, so now I will drain according to your directions. Should I turn off the auto fill and just re-fill it by hand. I guess I will also have to turn off the pump if I end up having to drain a lot of water, right?
Also, I have a bad algae problem since the salt cell isn't working. What should I do about that? I have put chlorine in twice now, and it is all gone, its like throwing it away...
Thank you again for your help!

 Reply

InyoPools Product Specialist  Posted: 12/5/2016 

high salt level - See our guide on "How To Remove Calcium Scale Deposits From Your Pool Wall". Most people do not seal the tile after cleaning it. You will have less buildup if you maintain good chemical balance.
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Anonymous  Posted: 12/3/2016 

Follow up question to the high salt level affecting the glass tiles---We have a pool service that checks the chemical composition of the water every week, but we still have the pitting and the heavy calcium build up. Based on the fact that the pool was maintained, do you have any idea what could be causing this? How would you recommend cleaning the tile and would you use a sealer after the cleaning? thanks!
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InyoPools Product Specialist  Posted: 11/4/2016 

high salt level - High salt levels should not affect the glass tiles, but you do increase the risk of metal corrosion in your pool system. If the rest of you chemical levels have also been ignored for a year, you can have pitting in the pool walls and a white calcium buildup on the glass tiles.
 Reply