PH - H2SO4 / HCl?

[GDA]

I've never thought about the difference in PH reducers.
During a year and a half I used PH reducer that contains HCl.
But half a year ago I bought PH reducer (H2SO4), not thinking about the difference in it.
a month or two ago I've noticed white stains on the surface, tried to clean, but no results.
Can PH- (H2SO4) cause it? What do you think? Maybe someone had the same... How to get rid of it?
Thanks for any help.

 

[PaulR]

White stains might be calcium scale. Please post a full set of test results (pH, TA, CH, CYA, salt if you use a SWG) and we can see whether that indicates a problem.
--paulr