On 16/09/2014 14:01, soup wrote:

My son has asked me to put a tap in to drain his trough (it is filled
with stones, plants sit on top of the stones and water).
Are there any 'kits' around to do this, has anyone done this using off
the shelf plumbing parts are there any 'gotchas' I have to look out for?

I have a LOT of water to clear. Glove should give some idea of scale,
stones scraped out of the way to try to illustrate just how much water
is in this thing.
http://postimg.org/image/q8g7gfu7l/

Where I intend to mount the tap (hadn't realised just how grotty the
Greenhouse had become).
http://postimg.org/image/s0p76dz4x/

People involved in home-brewing sometimes modify barrels to add taps to
them and it is easy to do; once you have drilled the hole through, you
can add the tap via a bung. There might be better, more permanent ways
of achieving the same thing, of course.