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Re: Halogen lights, Re: 10 gallon lighting (APD V3 #1199)

> From: Andy Goss <Andy at Goss_net>
>  I have a 20 gallon tank that I am wanting to plant.  I noticed that the
>  original hood has a single 18" 15 watt bulb.  I am wanting to find
>  something that will provide 2-3 watts per gallon.
>  I have seen a Halogen strip light used for accent lighting that is rated
>  at 75 watts (3 - 25 watt bulbs).  Would this be sufficient?  Are there
>  any concerns about using Halogen lights versus Florescent or regular
>  Incandescent.

Oh my, where to begin?  

Halogen lights provide very high quality light, but the are inefficient and 
produce a lot of heat.  The "watts per gallon" rule assumes you are using 
reasonably efficient electrical discharge lights, like fluorescent or metal 
halide.  Incandescent lamps (like the halogens) peak out at about 20 lumens 
per watt, only acheivable with very high wattage lamps.  Mostly they produce 
heat. You also won't find the color to be very attractive because the color 
temperature will be about 3000K and look kind of yellowish.  The three 25W 
halogen lamps you are talking about will produce a barely noticable increase 
in light output compared to your 15W fluorescent.  The halogen lights will 
provide uneven illumination with "hot" spots, which actually might be a nice 

Fluorescent lamps peak out in efficiency at about 100 lumens per watt, only 
achievable with some 4 foot and 8 foot lamps.  So, generally you get about 5 
times as much light from a fluorescent lamp as an equivalent wattage 
incandescent or halogen lamp.

I am currently using a single 40W compact fluorescent lamp (overdriven to 
about 45W) on my 20H tank.  I produces *plenty* of light for my needs using a 
F40/30BX/RS/SPX41 lamp from GE.   I will replace the bulb with a SPX50 when I 
relamp because the SPX41 is a bit too yellow.  Also, With the ballast I got I 
can add a second lamp later if I need to.  I built my lighting from scratch, 
both on my 20 gallon and a 10 gallon, and you would not believe how much 
trouble it is finding information about the components, and finding some of 
the parts (like 2G11 lampholders) is a nightmare.

There is a company that I think is called Aquarium Hobbyist Supply at 
www.ahsupply.com that sells kits with reflectors, lampholders, ballasts, etc. 
for very reasonable prices.  I have not actually seen one of their kits, but 
I have discussed some technical issues about their ballasts with them and 
they seem knowlegable.  You might seriously consider using one of the 22" 
kits (40W or 55W).  It should retrofit in your existing hood if that's what 
you want.

They also have a 36W kit that uses a 16" lamp that should be perfect for a 10 
gallon or 15H tank.

I hope someone finds this useful.  I will try to be briefer next time :-)