??
A half a gallon
is 2 liters. That would be 100% of pot size. My mix can hold about 20-25% of pot size max of water. More than that and your flushing or wasting nutrients.
@empath , Proper watering is one of the most common issues plaguing growers, and not just new growers. There are several ways to get after it.
Emilya has a good thread on
How to water a Potted Plant
Others, like
@Bill284, add extra layers of perlite in their mix to help with drainage
And, a number of us have switched to growing in SIPs (Sub Irrigated Planters) which gives you perfect watering every time since the plant waters itself. Come check out
#SIP Club for more detail.