".........Wish I could afford 'experiments' like that;......."

Well my fogger cost £9.95 from Maplin (special offer)
uses around 3/4 pint of water an hour on continuous running, but with a
timer I am going to try 15 mins on 15 mins off, You get more fog from warm
water so if it is in contact with the soil warming cable should work better.
Will probably require a very low volume fan but should find something low
cost, only need around 3inch.
The larger fogging machines such as they use in disco's seem not to run on
water.....pity as for under £40 you can get a machine with quite an output
(Maplin do one for £44.00 that has an output of 2,500 cubic feet per
minute).
With that you could do a whole glasshouse minute.
did see 2 at a trade show One £800+ and the other around £1400.
The control unit for Mist is getting on for £200 so this could be a much
more cost effective system and not put out so much water, so that things
like Dahlias that don't like being wet could benefit.

--
David Hill
Abacus nurseries
www.abacus-nurseries.co.uk