pogledala sam onaj link na wikipediju:

Ammonium alum
Ammonia alum, NH4Al(SO4)2·12H2O, a white crystalline double sulfate of aluminium, is used in water purification, in vegetable glues, in porcelain cements, in natural deodorants (though potassium alum is more commonly used), in tanning, dyeing and in fireproofing textiles.

Je li to onda loše ili ne, nekakav spoj aluminija je? U čemu se razlikuje od potassium aluma?