Some people (Europe) won't start a reef tank until sponges are growing. Some like encrusting sponges are pests. Others add color or unique interest to your tank. I recommend you use this poll as an opportunity to learn a little about the mushrooms in the poll.
Here is one sponge photobombing a harlequin shrimp. Feel free to post yours below.
Here is one sponge photobombing a harlequin shrimp. Feel free to post yours below.