Butterflyfish in Your Reef?! In this episode, we discuss the most noticed fish in our tank, the Yellow Pyramid Butterflyfish. While most butterflyfish aren't great inhabitants in reef tanks, nipping and destroying coral, Yellow Pyramid Butterflies are the exception to the rule. We'll share the best size tank for this type of fish, in addition to our thoughts on temperament and adding duos and trios of butterflies to your tank.