oaway (Zerex) wrote in
:

I have a 20-gallon TALL tank that I am going to plant. I plan on
getting a light kit from AH Supply, but I'm not sure what I should get
to light this tank. I know I'm gonna need a lot of light since the
tank is so deep, but beyond that, I'm clueless as to how much light
I'll need. Any suggestions?

From http://faq.thekrib.com/ (note, though not mentioned at the
website, measure your surface area and light depth in inches):

When calculating the amount of lighting you will need there is a general of
thumb. First multiply the surface area of the aquarium by the distance from
the light source to the top of the gravel. Then depending on the type of
plants you desire multiply this by one of the factors given below.


Low light plants 0.08
Low to Moderate light plants 0.12
Moderate to Bright light plants 0.18
Bright light plants 0.27

This will give you the ideal watt hours of fluorescent lighting that you
need. Divide this number by 11 and you now have the approximate total
wattage of lights you need. Unfortunately this number may not be equal to
what is available in bulbs so find the combination of wattage that will
most closely match this requirement and adjust the available time to match
the watt hour calculation.
Example