This should help with watering!

[Andy H]

Thought I would try this, so put together a few bits of wood and plastic and filled with water. Should hold enough for the hottest days in the greenhouse.

[Andy H]

[emmy1978]

Very smart!  ;D

[allaboutliverpool]

Don't keep it full of water otherwise they get too wet, tomatoes are not bog plants and you will get blossom end rot if they are too waterlogged.
However it is otherwise a great cheap solution.

http://www.allaboutliverpool.com/allaboutallotments1_homepage.html

[Andy H]

Yep wondered about that, I will let them dry out for a bit before re-filling.