How much water should I program my drip system to dispense to a 5-gal container?

For example, do I set it to drip the equivalent of 1/2 gallon per day? More? Less?

I assume the quantity of water is the same regardless of whether I add water myself or via the drip system?

Naturally, I understand quantity and frequency varies as we get into higher summer temps. I am in Houston, FYI.