I bought a MH retro kit last week and got it today. 2x 175w Venture
5K bulbs, sockets, and good old Advance core/coil ballasts (in nify
aluminum heatsink/box) all cabling, and a nice reflector. From Cool
Touch Lighting in Canada - $289 for everything including shipping via
UPS to the US.

Firstly, it took 7 hours to mount the reflector, sockets, build a pair
of T12 reflectors w/sockets (4" PVC cut in 1/3 pieces and sockets
screwed to the ends) to hold 6500K bulbs/wire to ballasts all into my
canopy. The Venture bulbs look great over my 75 gal freshwater
planted tank. Previously I have been using 4x T12s (2x Chroma 50s,
and 2x Ultra Daylight 65s) but they never came close to the quality
light this new MH setup makes. The plants look more brilliant, the
fish look happier, I have a realistic 'sparkle' at the bottom of the
tank, and most importantly I now have steady streams of bubbles coming
from nearly every plant and noticed at least an inch of growth (!) in
several hours. My tank is CO2 injected via a 20lbs bottle regulated
to .5 lbs and controlled by a special valve made for my at my work (we
make precision digital flow controllers and meters) to hold about
18ppm CO2.

The tank is about 2.5 years old, but spent nearly a year sitting with
dead plants, fish and 90% evaporated water due to a move and
nowhere/time to get back into it. About 1.5 months ago I fixed the
filter and brought everything back to life (tank was still pretty much
cycled) and bought some new plants and fish. Things have been pretty
smooth except for the lack of light slowing plant growth. The
substrate is a mix of Peat Moss and sand for the bottom layer, and the
top is quartz gravel with a little laterite mixed in. I treat with
some trace element additives once a week and started adding some K
last week, once a week. I have a bit of brown algae on the glass and
gravel, but nothing serious. I'm hoping the new light allows the
plants to beat the algae.

Anyway, figured I'd post finally after following this group for years
but never having anything to say.

MH rules!

Dieter