Re: Lighting, from another angle

>From: George Booth <booth at hpmtlgb1_lvld.hp.com>
>You didn't mention what you were going to breed in these tanks, but
>for plants ...

For fish, I'd like to breed rams and Corydoras rabautii.  For plants, I'll
probably use Lilaeopsis brasiliensis, various crypts, Java fern, and maybe move
my lone nymphaea in one of these to try and get it to recover from my move
nearly a year ago.

I'll probably run the tanks with 4" substrate and 4" water, plus an airstone.
Most of the plants will grow partially emersed.  The lilaeopsis may need
additional consideration (13w CF).

>Assuming a single 24" 20W bulb with 1500 lumens (very generous)
>lighting a 24"x24" surface area gives 2,800 lux at the surface
>assuming a 70% reflector.  (Lux = lumens per square meter)

I'm looking at putting two tanks end-to-end, and possibly making a square
arrangement of all four tanks.  Since these tanks are 24" wide, I'll stretch
two 48" GE F32 T-8 SPX-50's across each pair of two (just picked up the
SPX-50's yesterday).  If the deep parabolics don't work, I'll switch to 4 tubes
per tank.

>2,800 lux isn't very bright for most plants. 

>7,000 to 10,000 lux is better.  We have 15,000 lux over our 20" tall

Since I'm setting these tanks up for emersed growth, I'm expecting to get away
with a lot less light.  My experience with emersed growth over water is that
you get about 3X-4X the amount of light to the emersed plants over water that
you get to submersed plants due to reflection at the water's surface.    

If it doesn't work, I'll try something else.  :-)

David Webb, in Plano TX, where it just got chilly.