Every time you water, water as slowly as you can,make sure your medium is mostly wet, before you pour a whole bucket of water on them.
If you don't the water will just run right out of your container, the water creates channels in the medium and will drain out right away (curse you gravity and surface tension). Give them all a quick splash ( a few cups all around the base), smoke a joint then finish all the watering, you carried the water all the way in, might as well make sure it's where you want it.
I water like this with everything from 6" to 6'
If the watering is to much, get them out of buckets, and into holes in the ground, that way if you miss a watering you are not stressing about your bone dry pots all day at work. lol