It’s not really that the stones allow the water to flow through as much as they help to prevent the soil from draining out. Personally, with very small holes I don’t beleive that you’ll need them and they might actually block the holes. Stones will also add weight to the container. If- on looking at the holes you’ve drilled – you think it’s likely that the planting medium will flowout, then add a layer of stones or even pottery shards, but if you don’t think you’ll lose the medium, you can skip the stones.
Lorraine

I am starting a balcony planter box which is 45″X20″ and I wanted to know if I should put stones in the bottom of the box to allow for water to flow through the tiny holes I drilled in the bottom.

What is your suggestion, if any about such stones?

Robert