Mushrooms are for sure reef safe. And they require very little lighting. I keep mine under an overhang and they are doing wonderfully.
Not sure about the urchins though, they dont interest me for some reason could be that they are known to knock over corals in their journeys through the tank LOL
180g Reef - 60g Rimless Reef -90G FOWLR- 125g Malawi Cichlids- 40b REEF- 34g Fresh Planted-working on- 20L FOWLR- working on
I have a mix of many different saltwater fish amongst my tanks, but I love my Tangs most of all.