Does anyone grow their own basil indoors?

I've had my container for about 4 months and I'm wondering when and what to start feeding it. I figure eventually the soil will get depleted but I don't know how to make it rich again. The people at the hardware store couldn't help since they told me everything they sold would "fry" it because the food is too strong. I only water it a little bit every few days and their foods required drops in gallons of water, so it's more for an outdoor massive garden setup. Can I put food detritus like banana peels on top of the dirt and let it decompose or what?