I have not put any food into the tank. I waited until there was enough general algae growth for the shrimp to get along okay. That said they are doing fine, but once I get the rest of the shrimp in, I will of course be feeding them. Four shrimp eat such a small amount and are too difficult to feed specifically that I just haven't bothered.
I'm not getting a fish that will eat the snails, because they would surely eat the shrimp. Scarlet Badis are about 1" long max with small mouths. Only a real threat to planarians, cyclops, blackworms that I intend to feed them, and shrimp
babies.
I've started doing about 20 min of snail removal a day so that should help.
The hardest part seems to be locating scarlet badis...
