When you wake up at 3am and go look at your tank with a flashlight to see whats behind the rocks! Then return to bed wondering what you didn't see! Debbie
When you buy a lighter not to light something, but because it has a blue led on the bottom and you plan to use it that night to see what's up in the tank.
when you have 72 different types of Zoa's.....in a 30g