RubenD wrote:
Everyone says the reference point to get lights are base on watts/gallon.
My question is how tall does the tank has to be in order to use that rule.

Does 3 W/G become 6W/G when you place the coral in the middle. For example
if you tank is 18" tall and you place the coral at 9" will you double the
light on them? how about at 15" up?

I ask because I've been seeing those nano cubes with 18-30 watts with nice
coral set up.

TIA

Ruben


Ruben,

Watts per gallon is the worst measurement for light just because of the
reasons you list. It does not take into account the depth of the tank
or where in the tank you are putting the creatures.

What you need to look at is how much light the coral needs and how much
light you have. A nano cube with 30 watts of light (say a 12 gallon) is
only 2.7 watts per gallon or so, while my 180 with 2 400 watt lights is
4.4 watts per gallon. Both of which are very low according to the watts
per gallon rules of thumb. My 180 is setup as a SPS tank and really has
intense lighting on each end of the tank, with no light in the middle.
While my nano has moderate light on the whole tank.

As for the depth, you are correct in that if you move the coral up in
the tank you will increase the amount of light on the coral but you do
not change the watts per gallon.

Kim