As the growhouse stops the plants recieving rain I decided to try micro-irrigtion. It comes with a gardnen computer to time the water automation, which feels the direction a geek gardener should go.
My understanding is also that herbs like to be watered in the morning so water can be absorbed during the day, and exess will evaporate in the warmth of the day. If watered at night the soil stays water logged overnight and promotes rot. So to try and optimise the process I purchased the Gardena Starter Set with C 14e Water Computer for micro-irrigation.