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sufficient lighting...

>Hi everyone!  I'm rather new to the hobby of keeping aquatic plants and 
>I've decided to set up one of my old 20 gal "high" tanks as planted 
>tank.  The only problem is that I can't figure out how to provide 
>sufficient lighting for the tank.  I figure that because the tank is 20 
>gal that I would want to provide 80 to 100 watts of light.  My one bulb 
>for the hood is only 15 watts!!  How could I provide enough light?  Is 
>there anyway to build my own hood (perhaps 4 bulbs in the fixture)?  
>Could anybody offer some possible solutions?  Any answer (or multiple 
>answers :) ) would be appreciated!

My rant for the day :-)

This is another area where many people seem to be falling into the common
American faulty thinking, "If some is good, more must be better".  While
15W on a 20G tank is certainly on the dim side,  80-100W is _WAY_ in the
other direction.  I see no good reason to use light levels this high.  I
have _never_ failed with a plant for lighting reasons with light in the
3W/G range in a tank of less than 22" in depth. (some people seem to feel
that these higher levels are necessary in deeper tanks, and since I've
never worked with a deeper tank personally, I can't comment)  Beyond 3W/G
on a smaller tank, and you are simply wasting money on electricity, and
guaranteeing that you will need to use more supplemental CO2 and trace
elements than in a more moderately lit tank.  I am not suggesting that it
isn't possible to reach a steady state in a tank like this, but it
certainly won't be easier, and it _might_ be harder than with 3W/G.

Personally, I run the two 20H tanks that we have with 40W over each.
(easily accomplished with 2 20W strip lights)  Both have _excellent_
growth, and contain many species including several "high light" species
like Bacopa, Acorus, Lilaeopsis and Rotala macrandra.  All of these plants
grow well enough to require regular division, and are lush and green.
(Rotala is lush and red<g>)


Karen Randall
Aquatic Gardeners Association