corals as natural protozoa filters

[amir basis]

hi everyone,
my clownfish developed a few days ago ich the covered all of him. its like the 4 time in the last 5 months and it always disappear on its own without treatment.
while i was looking at him it got me thinking-can corals feed on protozoas such as marine ich and other parasites that are free floating in the tank? after all ,they do posses a nutritional value and they are in the right size(free swimming ich about 150 microns) for many types of coral's polyps.
im not suggesting that corals can 'clean up' the water and act like uv or ozone sterilisation but rather as a contributing factor in limiting the amount of infectious protozoa in the water through their natural pry catching.

your thoughts?

 

[Journeyman]

I saw a nature video where dolphins would rub themselves on a coral, which had some kind of natural anti bacterial effect.

Now I can't remember the name of the movie or the coral. Maybe planet ocean or something like that.