Re: Low Light, Slow Grow Tank

["roger" <roger at spinn_net>]

Kirk Melton wrote:

> I was wondering though, at what point does a low light tank become
> a high light tank?

I break tanks down into low light, moderate light and high light.  The
boundaries between the three categories are nebulous.  Watts per gallon gives
us the only working measure, and that is subject to huge variations.  By that
rule I usually regard tanks with 1.75 watts/gallon or less as low light, tanks
with 1.75-3 watts/gallon as moderate light and lights with more than 3
watts/gallon as high light.

With those limits, your 72 with 40 more watts added would still be a low-light
tank.  Your tank at home would be moderately lit with all the lights on, but
on the border of low light with the 40 watt strip light off.

The guidelines are extremely rough  For instance, my 150 gallon tank at home
has 2.2 watts per gallon provided by cf lights with good reflectors.  It is
*way* brighter than my 10 gallon tanks that have 3 watts/gallon provided by
15-watt T8 lamps.

Concentrating the light at the back of the tank will let you grow a few plants
that you couldn't otherwise grow.  You will have to try a few of the
borderline plants (like E. bleheri) to know if you can do it.  For quite a
while I had a 55 gallon tank lit with 60 watts of light -- one 40 watt strip
light and a 20 watt light sitting at one end of the tank.  The end of the tank
that was under both tubes could grow a lot of plants that one would grow in
moderately-lit tanks.  The other end grew anubias and crypts.


Roger Miller