Just have your plant container sitting on top of a water collection plate.

In watering the plant from the bottom, you need a lot of patience. The lava rock will quickly absorb much of the water, but it takes a while for the soil to absorb the water from the rocks.

Also, you should only do this in 12 quart or larger containers as the roots will indeed grow under and around the rocks. Give them room in the soil.

You will need to water much more frequently using this method as well. For this to work, you do not want to let the rocks dry out, as this will also dry out the roots that take over the base of lava rock.

Also water temp is VERY important here, lest you give your roots a shock of cold water...warm water is best.

Nutes are another issue. Be very careful not to burn the roots with this watering technique. Remember, this method removes the protection of the soil base in buffering any dangerous counts of nutes.

Watering from the bottom is very effective and usefull but it takes a lot more attention in time than topside watering.

Finally, when watering from the bottom, never let the water level get above the top level of rock. At this point you will be saturating the soil. One of the benefits to lava rock is the mineral content. (red rock only)...

When water is above the rock line, there is less mineral transport available to the soil. Keep the bottom moist at all times. Once you see it completely dry, get some water in there.

Once in a while, its good to also water from the topsides. Especially when nuting.

HARD