Not sure if someone mentioned it but just use hatching decapsulated brine shrimp. Muuuuuch easier.
I kept 2 ruby red's alive in a 75 that didn't have much sand like this.
They didn't just "survive" but grew and were constantly fat. (was concerned how fat the female was when she had eggs too lol)
Tons easier than culturing pods or hatching bbs all the time.
I just broadcast now, but when I had the ruby red's I would use a small diameter pipe down to a pill bottle with a small hole in it. Then when the shrimp hatch they can enter the tank. Just a couple drops in the pipe once a day.
I get mine from a dude in florida, can't member the name, just search ebay. Be sure though no matter where you get them, they MUST say 'hatching'. There's a couple different ways to decapsulate brine shrimp eggs, not all are equal.