In our area it is the most common product used. The issue with scale requires a question first. Is it recent or not? ScaleTec will give dosing for removal vs prevention and as a prevention it is pretty good. I've never found any remover that does any good. I use the word prevention loosely as there is no substitute for good chemistry. Here's an example. I acid washed a black bottom pool about 2 months ago for a guy who then went on to hire a service guy who pretty much did not keep tabs on the pool knowing it has a poor water source. The pool developed a scale about the same as that of 80 grit sandpaper. The previous guy added 2 qts of ScaleTec and it basically feathered off a bit of scale but did not touch the sandpaper like stuff. I came back to see it last week and dosed the pool down to about a 5.0 pH for 4 days. Revisited the pool today and there is little success. Owner is ready to acid wash lightly again to remove the white haze. Bottom line, ScaleTec is no miracle worker on this one.