Kev txhim kho kev ua tiav ntawm cov txheej txheem dej yuav hloov cov khoom siv kho dej siv cov txheej txheem tshuaj thiab cov txheej txheem pom.Nws muaj kev nyab xeeb thiab yooj yim rau siv, yeej tsis muaj nqi, thiab cov nyhuv tau mus txog qhov ntsuas zoo tshaj plaws.
Tom qab kev teeb tsa thiab siv rau ntawm lub raj xa dej, nws tuaj yeem ua kom tsis muaj menyuam, tua cov algae, hloov dej kom zoo thiab tshem tawm cov fungi qub hauv cov kav dej.(organic scaling).