Draining a Salt Water Pool

[Loren42]

Rut Ro! What happens when I need to replace my pool's vinyl liner and drain 20,000 gallons of saltwater on my lawn?

Feeling a bit like Odysseus here sowing 600 pounds of salt.

 

[Texas Splash]

happens when I need to replace my pool's vinyl liner and drain 20,000 gallons of saltwater on my lawn?

Potential side effects on your lawn can vary depending on chemical content and condition of existing grass/sol. Sometimes it kills the grass, for some others no effect at all. Hard to say. You might try pouring some pool water in an area as a test. It may take 3-4 days before you see any changes though.

 

[Getitrite]

Some opinions have been expressed here.

 

[Loren42]

This was a question to understand what the ramifications of going to a salt water pool. We don't have city water or sewer and rely on a well and a septic system, so my lawn is the repository of draining water from rain and the 5 to 7 year maintenance cycle to replace the in-ground vinyl liner. Maybe we can do better to stretch that interval, but at some point the pool gets drained.

I suppose I could mix up a concentration of 3,000 ppm and test it on a section of lawn, which isn't that robust to start with.

 

[mknauss]

If you can drain your pool to your lawn, your drainage must be really good. Sandy soil? With the amount of rain you get, it would surprise be that a low salinity water would be an issue. A test would be good.

What is the salinity of the water in the pool now?

 

[Loren42]

No salt right now. I am debating with the idea of converting to a salt pool, but first want to understand all the good and bad that comes with it. In the next few years we are going to need a new liner. The last company was able to capture 1/3 of the pool's water, but not all. No assurance we can do that again.

I like the idea of going salt and stopping the liquid chlorine I'm using now. I just want to be sure I would be moving to a better situation and not necessarily trading one set of problems for another. So, I am asking as many questions as I can think of.

Also, our soil is sandy, so water does not pool very long, even under heavy rain (the rare 10" or more we get).

 

[mknauss]

How are you chlorinating? Liquid chlorine, trichlor, dichlor, muriatic acid, all add salt to your pool water. You might be surprised what the salinity of your pool water is.

 

[Loren42]

Liquid. My CYA is about 150. Need to get my well fixed and then drain off some water and refill before I do anything.

 

[Griswald]

A little bit of pool water won't be an issue, but 20000 gallons all at once is probably a bad idea.

 

[Loren42]

Yeah. Last time the liner was replaced we dumped about 13K of (unsalted) water. Not many outfits could capture water at all, so I thought I was fortunate to get back what we had.

 

[mgtfp]

Yeah. Last time the liner was replaced we dumped about 13K of (unsalted) water.

Where Marty was going with his remark, was that all forms of chlorine that you add to the pool get eventually turned into chloride (salt), same with muriatic acid, also known as hydrochloric acid. After several years of adding chlorine, the salt content can easily be up to half the level of a salt pool, depending on the amount of rain-overflow, splash-out and backwashing.

Might be worth testing the salt content of your water. Unknowingly, you might already have done your experiment last time you drained the pool.