I had a 2 gallon acrylic betta tank lying around and decided to put it in my 55 gallon saltwater tank to use sort of like a refugium to grow pods and macro in. Can someone give me some suggestions about getting water to move in and out of this small tank. I have it sitting right in the bottom of my other tank. It is hex shaped and has a clear lid with an airline slot and hole for feeding. Any help would be greatly appreciated.