[TheOldSalt]

Gonios are not easy to keep, no matter how brown they are, because they need something that most reef tanks do not provide. They'll be fine under actual sunlight, but not under aquarium lights. They don't come from reef areas, you see, but from grassy & muddy lagoons. They like their water dirtier with more food to eat, and they like some infrared light. You can keep them if you plan for this, but your other tank inhabitants won't like it one bit, unless you again plan for that and pick just the right ones. So, the "secret" you heard is actually just a big fat lie. Don't mess with Gonios. Just don't.

To put it simply, the brown algae that makes it all possible does it by providing oxygen and food and vitamins on a cellular level, while also getting rid of the waste and CO2. The algae serve very much like a built-in filter for the coral's very cells, thusly doing half the work for us.

Corals and anemones without these symbiotic algae don't have this advantage, which means that we have to do all the work ourselves, and it's not easy work.