• Ib lub pas dej txhuam hniav tuaj yeem tiv thaiv cov nplais (cov dej hauv pas dej nqus cov khoom ntawm cov huab cua sab nraud, tom qab ntawd khom rau hauv qab, thaum kawg tsim ua cov txheej txheem ntawm cov nplais zaj duab xis) / tiv thaiv stains (Pols stains feem ntau yog sib xyaw ntawm spores, kab mob, av, minerals. , roj lossis los ntawm cov khoom me me hauv lub pas dej ua ke) / tiv thaiv algae (Algae tuaj yeem nrhiav tau ib qho chaw npaj khoom noj plua plav thiab tsim kom muaj kev ruaj ntseg hauv cov dej qias neeg) thiab tiv thaiv etching.