Wow! How long does that last you?
It is so hard to say. First, half of that will go to my friend Scott who has WAY more tanks than I do. ...still 21 pounds of food is a lot. Keep in mind that 2.2 lbs is a lot and the cubes trays of mysis are usually 3.5 ounces. I feed more frozen when I am not coaching or not too busy with my business, but this should last about 6-8 months.
You can get those baskets at any place that sells pond stuff... or online.