Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
The traditional 55 gallon is a very narrow tank, and fairly tall. Hard to 'scape.
For the 4' length, if you can think about a deeper (wall to front of tank) tank, this would allow much more scope for scaping, yet take just a little more floor space.
If your tank is roughly as deep as it is tall, the scaping works better. More room for that 3-D effect, which is tricky anyway.
In as narrow a tank as the 55 gallon it is very difficult to add hardscape materials or plant plants in layers, or back-middle-front layouts.
This is also pretty bad when you are thinking about low light. The tall tank with so little depth does not allow a reasonable amount of light to reach the bottom.
A tank that allows you to put 2 fixtures, or a slightly bigger one over it can still be low tech, but you will get better light to the floor of the tank. Less loss out the sides.