Sprout watering is done mainly using an automated "micro irrigation" system.

The plumbing is done using Hozelock micro- irrigation supply tubing and fittings.

However I found the Hozelock misting nozzles to be inadequate.

The best misting nozzles I've found are those supplied by Norman Garden Products. These are relatively expensive - but they do the job.

Fortunately I found their screw fitting is about the same size as the Hozelock misters - so they can be simply screwed into the (cheap and convenient) Hozelock supply tubing.

More details of what misting and micro-irrigation systems are available can be found on this site's links page.

In this photograph, it can be seen that water is being supplied by misters - from above - using two misting jets per seed tray - and that each shelf has its own flow-control valve.

Water drips down from holes in the bottom of each gravel tray onto the trays below it.

When the water reaches the bottom shelf, it goes into a slanted drip tray.

The drip trays channels the moisture into the waste water bucket.

The exits from the drip trays can be seen here:

The drip trays are made out of wood - and are lined with thick PVC. I would have used plastic trays - but I couldn't find any the right size.

Water containers

Unfortunately, my sprout farm is not currently anywhere near a water source - or a drain.

Consequently I pump water between two water containers - pictured here:

The one of the left is the waste water container. The two hoses going into is are the ones from the drip trays (above).

The one on the right is the fresh water container - containing the pump.

Pump

I use this 250 Watt sumbersible pump to drive water through the system:

The pump is attached to a programmable mains timer - which turns the water on at regular intervals throughout the day.

Manual watering

I also do some manual watering.

I do that using this 7-litre garden pressure spray:

Capillary matting

While watering, some of the supplied water drains into the enclosing gravel tray.

This is lined with capillary matting - which is intended to retain excess moisture - and to help redistribute any excess evenly.