where does the calcium go with scale removers?

[jrmeyer]

Scale and stain removers (sodium hydroxide) purport to reduce calcium levels in the water. Where does the calcium go? (pool store said "it degrades", but fission doesn't happen with calcium). if it precipitates, what keeps it from scaling? Basically, how do scale and stain removers eliminate calcium without hurting the plaster?

23k, plaster, 3HP Intelliflo, 460sqft cartridge filter, Hayward Swimpure SWG, Cat1000 pH controller(which is great).

 

[JasonLion]

They don't, the calcium is removed from both the scale and the plaster and ends up in the water. For a while the product will prevent the calcium from redepositing as scale, but all of those products break down eventually, at which point the calcium can again cause further scaling (unless you replaced water in the mean time).

In most cases, calcium is removed from scale much more quickly than it is from plaster, but there is always some of each happening.