Evacuate the Run-off
The plants should be watered until run-off at each fertigation – and they cannot sit in that water! There are several solutions for eliminating run-off water. Many growers move their plants around to water them, but plants don’t like to be moved and this becomes impractical. Other growers use shop vacs to suck up the run-off from each saucer. When practicing high frequency fertigation, self-draining saucers are really the only way to go.
This solution requires some effort to build, but I believe that the effort it saves during the grow is well worth it. Self-draining saucers are great if hand-watering: No moving plants, no hauling around noisy shop-vacs, simple – easy. If you hope to fully automate your system they are absolutely mandatory.
I use two saucers with 2x4s between them to elevate. This does cost 3.5” of vertical, but that is all that is needed to gravity drain. I attach drain lines which use gravity to drain all my saucers into one common catchment. Be sure to check out my tutorial on "Catchment Solutions", but first you need to put together your self-draining saucers!
Step 1: Attach drain lines to top saucers
- SuperGlue cone washers to drain line
- Drill ½” hole near edge of top saucer
- SuperGlue cone washer (with drain line) to underside of top saucer
Step 2: Attach 2x4s to bottom saucer
Arrange 2x4s like this in the bottom of the saucer. The drain hole will be positioned over the unsupported area.
- Drill through bottom of saucer and into the 2x4s. 2 screw holes per 2x4.
- Apply silicone sealant/caulk in screw hole
- Screw in from bottom until head of screw is pressed into and flush with bottom of saucer.
Step 3: Assemble
- Drill ½” hole for drain line to pass through edge of bottom saucer (see pic below)
- Feed drain line through that hole until top saucer is positioned above bottom saucer
- Drill holes from the top – apply caulk before the screw - 2 screws per 2x4
Step 4: Install
- Keep lines below the level of the saucers.
- Run all lines to a "Catchment Solution"