chlorine advantage: Chlorine also helps eliminate slime bacteria, molds and algae 

disadvantage: disadvantage of producing toxic disinfection by-products.

iodine advantage:  It helps to regulate the production of the thyroid hormones thyroxine 

disadvantage: Both too much and too little iodine can lead to goiter and other thyroid problems. For this reason, it is important to speak to a doctor before taking iodine supplements

quaternary ammonium advantage: QACs are more effective at cleaning, do not damage clothing and carpets, have less of an odor

disadvantage: When quaternary ammonium is mixed with organic matter it loses its effectiveness

Explanation:

here I hope it helps you :))