“TESTED FOR FRESHWATER ONLY”

[AW139]

I have a System 3 S7M120 cartridge filter, currently using liquid chlorine. I’m planning on switching to a SWCG next spring, and just noticed that my filter has “TESTED FOR FRESHWATER ONLY” printed on the label.

Is this of any concern when switching to a salt system? Thanks!

 

[Donldson]

Generally "Fresh Water" is in contrast to ocean water, which is 35,000 ppm salt. A salt pool is 1/10th of that at most.

On top of that the phrase "tested for freshwater" is a long ways from "not to be used with saltwater". Most likely just covering themselves. Personally I wouldn't let it dissuade me.

 

[proavia]

You should be fine.
I think they put that on there so people don't filter pond, lake or ocean water thru it.
Should go without saying not to filter anything thru it that is not a pool or spa.

A chlorine pool has salt in it. And if the water has not been replaced within the last 3-5 years, chances are that pool would have close to the salt level required for SWG use.

 

[JJ_Tex]

Interesting. Here is the manual and I didn't see anything about no salt or freshwater only.

https://www.pentair.com/content/dam/extranet/nam/product-related/product-manuals/pool-and-spa-equipment/filters/System-3_SM_Owners_Manual_English.pdf

 

[AW139]

Thanks everyone. I figured there was nothing to be concerned with, but wanted to check before I dropped a couple grand on a SWG just to find out I need to drop a couple more grand on a new filter.

 

[DavidArmenB]

You’d be surprised how much salt is already in your pool. Whenever you convert, be sure to test the current concentration before adding any salt, because otherwise you will absolutely overshoot by a large amount if you assume your starting concentration is 0ppm.

 

[Newdude]

While there are several conflicting authorities on the matter, freshwater may have up to 5k ppm salt per some of them, and 3k ppm salt per the others.

'Salt pools' are about 3500 so even using the more stringent 3k threshold, they'd barely be brackish water and behave more like freshwater versus the seawater side of brackish water at 30,000 ppm. For the slightly more lenient standards, a 'salt pool' is freshwater.