Is coral covered live rock still a viable filtration media, or a nutrient trap ?

[lockrookie]

When I started up I was told as a rule one pound per gallon 4 inches of sand use Dt water for quick cycle

Now it's minimal rock is fine but lots of corals remove all your sand. And Dt water not helpful

This hobby is so interesting and confusing all at the same time. The times they be changing lol