I have an elevated spa that overflows into the pool via a waterfall. The 6" tiles on the face of the waterfall continue to get a white build up. at first, I thought it was calcium build up but my chems are all in balance and I don't get any build up anywhere else. That is when I read about efflorescence. Either way, I have been eliminating them with an acid/ water mix via spray bottle. The build up does react to the acid. But it comes back so quickly now.
Any thoughts on whether it is efflorescence or calcium scale?? Also, has anyone tried these tile sealants that claim to prevent efflorescence?? If so, do they work?? Photos attached- if the upload works.