I have a two gallon hex with two dwarf aquatic frogs (male and female) and an oto. I feed my frogs shrimp pellets that sink to the bottom of the tank. The problem is, my female is biggger than my male and she's getting all the food. So she is very overweight and my male is really skinny and weak. (Also I checked to make sure she wasn't just pregnant, and she is not) How do I get her to stop eating all the food?