The purple stuff for salt system

[Guest]

Has anyone used The Purple Stuff for their salt system? What does it do?
Thanks.

[chem geek]

The Purple Stuff is a metal sequestrant that works well in the high salt levels of SWG pools. It helps prevent metal staining and prevents buildup of scale in the salt cell.

If you don't have dissolved metals (iron, copper, manganese) in the water, then you don't need this product. You can prevent scaling in the salt cell by maintaining an appropriate saturation index close to zero, but slightly negative (perhaps targetting -0.2 or -0.1). You can use The Pool Calculator for this, but be sure to include the correct salt level and temperature (as well as pH, TA, CH, CYA) as that affects the index.

To prevent the pH rise normally associated with SWG pools, you can target a lower TA level (usually 80 ppm) and raise the CH or target pH (around 7.7) appropriately. You can also use 50 ppm Borates in the pool as an additional pH buffer and this also helps prevent scaling in the salt cell. See Water Balance for SWGs for more info.

Richard

[Guest]

Thanks. I also really appreciate the references. I've had a salt system for 11 years, but I think I need to go back to the basics since I've always had problems with calcium carbonate buildup and add 1/2 gallon of muriatic acid weekly. We are replastering and my wife wants this pebble tech stuff and she said their site recommends this purple stuff.

I read your forum on pebble tech, seems like half like it half don't. Thank you again for the resources.