I *think* that you can use the 34 watt bulbs...more below.
>I can't find anything that tells whether you can mix these 25W night
>lites with 40W growlights.
A very good question. I couldn't get anyone at the hardware store to
answer my questions...and I don't imagine I would have trusted them to
have the correct information anyway. So I called the "Light Bulb
Store". All they sell is light bulbs so I thought their information
might be accurate. However I make no guarantees. I was told that you
can mix bulbs within a 4 bulb fixture, however you need to mix them in
pairs. Most 4 bulb fixtures have two ballasts inside and you can run
two 25 watt bulbs or two 34 watt bulbs off of one of the ballasts and a
pair of 40 watt bulbs off of the other ballast. You'll have to look
inside the fixture to see how it is wired to make sure which sockets
are wired in pairs to each ballast.
>A warning says you cannot use the 34W in the old ballasts.
This is interesting. I have yet to see any such warning in any store,
although I believe that you did. I think Barry mentioned the same
warning. The Light Bulb Store told me that you can indeed place 34
watt bulbs into a 40 watt fixture. Here at the Superior Court they mix
34 watt bulbs with 40 watt bulbs with out even pairing them up, and
they DO NOT make any ballast changes. In fact the workers were unaware
that they were replacing burned out 40 watt bulbs with 34 watt bulbs
until I had them inspect the bulb's labeling! I'm not saying it's ok,
only that I have seen it done.
>My other choice seems to be buying new ballasts for all my fixtures,
>which will allow me to use 25W or 34W lamps. The one good thing is
>it looks like the new ballasts with a 34W will put out 3600 or so
lumens which is better (if I recall) than the the old 40W and old
ballasts. Again I can't find anything that indicates whether 40W
growlights will mix with the new ballasts.
The electronic ballast will also boost the lumens of a 40 watt bulb by
10%-15%. They do this by operating at a higher frequency (mHz). Also,
one new E-ballast will run all four bulbs in a fixture, or so I am told.
>(Nor have I seen any suggestion that growlights will also shift to
>the new standard.)
Me either.
>Will the screwhead who came up with this please stand up?
He is....... you just can't see him standing under the new 25 watt
lights ;)
John Walker