salt water spa

[ruturner]

Please help
after a long inactive time ( approximately 1 year), I finally got my salt water spa up and in use again. I apparently added too much salt to my spa such that the reading is at 4100 ppm salt. Does anyone have a formula to use to know how many gallons of this concentration should be removed and the same number of gallons of plain water to add back to reduce concentration to an optimal level ( eg 3100 ppm ). Trial and error is my only other option . I have a 860 gallon custom spa. Thanks in advance.

[Denniswiseman]

I would be inclined to take 25% out which when you fill with fresh water will have reduced the salt content by 25%

[Julia Ivanova]

Based on the ideal salt level (3000-3500 ppm), you need to use 30 pounds of salt for every 1000 gallons (information is taken from here https://www.discountsaltpool.com/how-to-add-salt-to-your-swimming-pool).

So, to count the perfect amount of salt for your water volume, you can use the following formula:
(30/1,000)*gallons=salt lbs

The amount of salt ppm is directly correlated with the amount of water. So you need to take water from your pool and add fresh water equal to the ratio of 4100/3100. So, 4100/3100 = 1.3225. And 860 gallons/1.3225 = 650.28 gallons. 860 - 650.28 = 209.72. You need to take out 209.72 gallons and replace the same amount with fresh water to get a 3100 salt ppm.