Calcium Oxide CaO cannot be mixed with halogen drugs such as bleaching powder and strong chlorin. Because bleaching powder is an acidic drug, and quicklime is an alkaline drug, if it is mixed, the acid and alkali will be neutralized, which will directly reduce the disinfection effect.

Calcium Oxide CaO and trichlorfon should not be used at the same time. Because quicklime meets water to generate hydrogen Calcium Oxide CaO, and under weak alkaline conditions, trichlorfon will undergo a chemical reaction to generate dichlorvos, its toxicity will be enhanced 10 times, and the residual period will be greatly prolonged.

It should not be mixed with organic complexes. The water-soluble organic complex forms insoluble complexes with calcium ions, which reduces the therapeutic effect of the complexes.

Cannot be used at the same time as copper sulfate. The increase of hydroxide ions in the water body will lead to the reduction of copper ions, greatly reducing the efficacy of copper sulfate. In the same way, quicklime cannot be mixed with calcium, magnesium and heavy metal salts.