...i personally aim for about 15% of the total volume for the res and i just eyeball it, i'm a lazy phuck by nature and this is a weed after all, ...anyway, all my containers are plastic and i make my drainage holes using a soldering iron and so i just poke the tip through the plastic and ream it out to clean it up and widen it a bit and it's done, ...takes about 5 seconds per pot, ...drill bits just slide around too much for my tastes, lol.Thanks for the quick reply Bobbo. My bucket is a little more than a half gallon, so I guess I'll drill at a little less than 1 inch. How big is your hole on that one gallon? 1/2 inch? 7/16? 3/8?
...so 3/8 is probably pretty close to what i end up with but i don't think you need to be too particular, as long as your media isn't washing out i'd say the hole isn't too big.
peace, bozo