How much can 2 african clawed frogs eat?

have 2 African clawed frogs and there both about 3 to 4 inches long not very big. And I bought 150 ghost shrimp and 1 rosie for them to eat thinking they would last for a good 2 weeks well they ate them all in 1 day no joke I have a lid on my tank so I know they didn't jump out and I moved stuff around looking for them but there is not even one left! I only bought 1 rosie because I was unsure if they could eat one because the rosie is half its size but nope its gone too! How much should I feed these hungry creatures and how often?