I might make a couple and experiment a bit with the food and see how I go.. I might have to change it to a birthday idea so I've got a bit more time. Thanks again.I don't think it's needed; It's just what I do. I have snails in 2 of the jars and don't feed them - I think the water has enough nitrate for them to find algae. Food should work too, but too much might crash the jar - they are very small. Maybe feed them every other week a teeny bit? I'm no expert.