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Re: Barry Barlow's MH lights

> To start the lighting system Im looking at is for horticulture, the price
> difference between these and aquarium built systems are emense(to say the
> least). Two 175 watt MH pendants would cost me at the very least $400.00
> American, For $150.00 less I can get one of these systems anywhere from 400
> to 1000 watts.
> My problem: the reflectors are designed to cover an area of 5'X5', My tank
> is 5' long(no problem) but the area covered in width would also be five foot
> seems to me to be alot of wasted light.
> Question: Do I need more wattage because of this?

You want to use a single 400 watt bulb to light a 5' tank I assume. I
think technically you are better off with two or three smaller lamps
spread out a bit. You don't need more wattage as much as a special
reflector hood.

I think you could use a single 250 watt bulb on a 5' tank so long as its
only about 18" deep. The low parts of the ends isn't going to be well
lit but you can put a bunch of stem plants in the ends and it won't be
much of a problem. I have a 4' tank lit that way. In one end I have
Rotala macrandra in the back and Hygrophila polysperma variegated in the
front of one end. I keep the H poly trimmed short and have to lop off a
foot or so of R mac every week or two and it looks quite nice. The
bottom part of the R mac isn't well lit and a little scraggly but its
well hidden behind the bushy H poly which is kept trimmed as a dense
foreground planting.

I would recommend that you find a pendant style fixture for the lamp
because the horticultural reflectors will send way too much light into
the room and blind you when you try to look in the direction of your
tank! For 400 and 1000 watt systems I think you'll have to have the
bulbs several feet above the water. You'd need a huge tank to use that
much light and you'd need some kind of a special reflector/hood possibly
a 5" high pyramid of inverted mirrors. I don't know of anybody using
that strong of lights on aquariums except maybe the Dupla 10000 litre
super aquarium aquarium. The used 10 250 watt MH lamps at a height of 1
meter from the water so presumably you could use 2 1000 watt lamps on a
1000 gallon tank. You'd probably want a few other lesser lamps to fill
in the shadows and corners.

I suppose one way to deal with light spilling out the front of a
rectangular tank is to put a low table with caster rollers and house
plants in front of it.

Steve P