Anyone have experience on black worm cultures. Right now I have a small culture hooked up to my aquaponics system. The aquaponics system consists of a 30 gallon tank hooked up to a 20 gallon gravel grow bed with lettuce and kale grown in it. The culture is one of those fry saver net things that hook on the inside of the tank. I use filter wool as the medium for the worms. I find that it's easier to deal with than gravel