re: osram lumilux

["Wayne Jones" <waj at mnsi_net>]

Gordon wrote:

I think you're right here ... I spoke with a inside sales person at
sylvania
and
he claimed the 860 is the highest kelvin bulb they make, at 6700k, that
8xx is their color rendering index (80+).

He claims the 950 has a higher cri of like 91 and is 5500k.  The guy at
osram was supprised to receive my call, as it was the second call he'd
gotten this week regarding these bulbs for a "non typical" lighting
application

------------------------------------------------------------------------
----------

These sound like the same lamps that AH Supply sell.

Gordon wrote:

I don't disagree that reflectors are important ... originally I was
lighting
my tank with a few t8 strip lights laying on the glass above the water,
talk about inefficent, most of the light was going into the room, rather
than the water.  The new hood I built is painted high-gloss white on the
inside with something called Painters Touch by Rustoleum.  It is a very
bright white, and made a huge difference on the t8's.  I'm sure polished
aluminum could do even better, but imho (for my own needs) this white
paint works really well, and is a lot easier then trying to polish and
bend
sheet aluminum myself, and a lot less expensive then a pre-made
reflector.

------------------------------------------------------------------------
------------

The paint is probably just as reflective than polished alumnium.
Polished surfaces are not necessarily highly reflective. The difference
is that AH Supplies specular reflector can direct the light toward the
bottom of the tank. This helps the light pass through the water surface
and puts light where you want it. The specular reflector reduces the
number of times a photon has to bounce off of a reflector and reduces
the chance of it being absorbed and never making it into the tank.
Without the special reflector you have a system that is no better and
probably worse than T8s. The PC system will however fit into a smaller
space than a T8 system. A good example would be lighting a 55 gallon
tank with 2 55 watt PCs and a painted reflector. The fixture would take
up 3" x 48" and provide about 9000 lumens. For much less money you could
make a T8 fixture using a ballast intended for 4 T8s. If you wire two
outputs together for each lamp and use 2 32 watt T8 amps you will also
have a fixture that produces about 9000 lumens. This fixture would take
up about 6" x 48" but it would still fit over the tank and provide
plenty of light for whatever plant you wanted to grow. The lamps in
either case would probably last about the same length of time and
provide the same lumen maintainance but the T8s are way cheaper at this
time. I would definately pick the T8 system. However, with a specular
reflector the PC system can do something the T8 system can't. It will
deliver more of the light to the bottom of a tank. That is why I said
that without the reflector you might as well go with T8s. Of course, if
you have a 2' or a 6' tank or no room for a 6" wide fixture then T8s are
not a good option anyway.

Gordon wrote:

Thanks for the tip on "hot wiring" the ballasts, I'll have to research
that!

------------------------------------------------------------------------
----------

There may be a problem with lamp life if you use that ballast from Home
Depot. It is instant start but the PCs are rapid start. Personally I
doubt if it matters much as aquarium lights are usually only switched on
and off once a day but it might matter. I am willing to let you take
that chance though ;-) You won't know for sure for a couple of years.
There is no problem doing this with 32 watt lamps as they are
specifically designed for instant starts. Both PCs and 32 watt T8s are
made for overdriving so that part is not a problem either.

Wayne