They are the only type of bulbs I've used and they put out a lot of light.
I've had to place a reflector over them to keep the light out of my eyes.
If one gets the highest wattage available (I've seen 45) they should be more
efficient than the tubes because one can put many more bulbs in the same
space. A good idea would be to fix a row of sockets to a board which can
then be hung over the plants or fixed to a plant stand.

Johanna



for orchids...

Has anybody tried compact fluorescents for orchid growth? It is
quite an interesting idea. The cost has come down substantially (over
50%) in the last couple years, so it is starting to be competitive in
terms of price. Still substantially more expensive than the equivalent
area of 4' tubes, I suspect. The cheap compacts are advertised as
having a life of 5 years, whatever that actually means. I can get the
equivalent of a 60W incandescent (I think that is 13W fluorescent?) for
about $3.50 on sale (which is the only way I buy them). Spend a little
more and get 7 years. It could be that these would need replacing less
often than 4' tubes (which I replaced every year or so). The energy
savings over incandescent bulbs would be substantial over the life of
the project. You would also generate less heat, important for confined
spaces.