I've had my pool for 5 years with it's SWG. At first, I would water down my acid to clean the generator and it worked just fine, and now it isn't. A little background, I'm in the desert and the calcium content is very high so the generator needs to be cleaned often. Sometimes as much as once a week. After a few acid cleanings I decided that much exposure to acid had to bad for it so I went to washing it out with a 1600 pound pressure washer. This worked well by just blowing the white stuff out of the generator. I did have to occasionally (6-8 months) acid wash it to get it back into shape though.
Then, one time when I dunked it into the acid I noticed it didn't bubble. There was white stuff in there, but no bubbles from the acid. The big stores here carry muriatic acid that is rated at around 15% so I started going to Leslie's for their 29% stuff early on. But now they are selling "White Muriatic Acid" This stuff is clear (no yellow) and doesn't fume very much when opened. And even a concentrated solution of this stuff won't bubble in a generator that has a lot of buildup. When I dump the residue on the alkaline ground here it bubbles a lot.
Have the physical laws changed recently and I missed the memo? What is White Muriatic acid? I know that the stuff used in special applications can be clear (no yellow), but the acid used in industry is normally a nasty yellow that fumes and causes your nose and eyes to burn. I hate to go to the stuff from Home Depot because I pay for half concentration at a tiny amount less money. Note though that I haven't tried the Home Depot stuff for cleaning in a couple of years; it may work.