Mechanical Filtration Necessary?

If you have a reef tank why not just stir the sump and keep the food in the water column for the corals to eat ? I stir mine several times a night pumps come on corals all eat for free . Maybe thats why I never had to target feed like many say they do ? Back when I was running bare bottom Berlins I did the same thing and as long at its floating it will either be skimmed out or eaten .

 

I don't target feed at all. I like to keep the nutrients out of the tank. IME sps don't need to "eat" as much as some think they do. I do however dose amino acids.

 

A protein skimmer is mechanical filtration.

Mechanical Filtration: physically removing something from the water.

Chemical Filtration: chemically altering a substance to where it is unharmful or easily removed via mechanical filtration.

Biological Filtration: mixing of aquarium water with bacteria by altering harmful substances into unharmful compounds. ie:being consumed by the tank and not manually removed.

In a sense, doing a water change because of nitrates or something similar is mechaical filtration.

 

what are the down falls of hermits?