There's really no point in them unless u just like to watch thats the only good thing about them is its funt to watch. High protein pellets such as masivore delite or carni sticks will grow your fish much quicker and provide a near perfect balance diet of protein fat and carbohydrates.
What fish are you looking to feed? I used to breed cons for my fronts but got rid of those and had to get rid of the cons since my new fish in my 50 grow out he did like to eat the con fry it's a bit of a setup but if you have time and space could be worth it