During test on passivated stainless steel, A black spot will appear when the surface has not been passivated correctly. Various qualities of passivation will give graduations of grey shades, ranging from light (acceptable) to dark (unacceptable) 1.00Box
it used to lower pH, maintain balanced water, and total alkalinity in swimming pools and spas/hot tubs. 25.00Kg.(PWD)
SODIUM HYDROXIDE FLAKES / PELLETS 25.00Kg.(PWD)
100 Gram Bottle STANNOUS CHLORIDE White Crystalline Powder 1.00Bottle Liq