This is what occupies my time when it is too hot or too cold to be outside.


It is a 55gal aquarium and contains mostly soft "medium light" corals and a few critters that serve as the cleanup crew.
Nothing spectacular about the tank, except that the aquarium is old enough that the rocks have taken over the task of biological filtering. It no longer needs artificial biological/chemical filters.

It is also getting close to becoming self sustaining, in terms of the food cycle. Tiny amphipods and crustaceans breed in amongst the rockwork and the fish and other critters feed on live food. I rarely need to drop in any fish food, and all critters are healthy.
Algae feed on light and bio waste > amphipods & other tiny crustaceans feed on the algae > fish feed on the amphipods > fish produce bio waste > algae feed on the bio waste.
The corals do their own thing and do not appear to disrupt the food cycle.