1. Hoʻonui ka paia apo i ka ikaika compressive kiʻekiʻe a me ke ola lawelawe lōʻihi.
2. He nui nā pore, kahi e hoʻomaikaʻi ai i ka mahi ʻana o nā bacteria maikaʻi.
3. ʻO ka ʻili nui, ka permeability wai maikaʻi, hoʻonui i ka ʻike oxygen i loko o ka wai a hoʻomaikaʻi i ka maikaʻi o ka wai.
4. Ka holo ʻana o ka ea maikaʻi, kahe wai maikaʻi ʻole.