Hi everyone,

TL;DR: Is there a general rule of thumb to calculate the number of LEDs needed for a vivarium based on its size?


I am planning to start a build within the next one to two months for Vietnamese Mossy Frogs. I've got an old 36x16x10 tank that I am going to use. Currently, I'm planning the lighting and will be purchasing this week. This will be my first LED build. I've been tinkering with them for a while for another project, so I'm not entirely new to LEDs. What is new, is using them for plants/animals.

I'm going to go with CREE XM-Ls; cool white and warm white. These seem to have decent coverage in the spectrums that encourage photosynthesis. They also appear to have higher light output than some of the similar LEDs.

My biggest question right now is figuring out how many I need to keep the plants healthy. I've found formulas related to reef tanks but not for vivariums. What is really throwing me off is the info I've seen suggests using a very high number of LEDs, 45-60, on tanks that are not all that much larger than mine. I can see needing more lights when water's involved, but is a similar number necessary for vivariums?

With the dimensions listed above, does anyone have any suggestions? I'll be using 40° optics, approx 4.5" above the top of the viv. Based on this, I can get full light coverage with three sets of lights; 7" from the left and right sides and then one set right in the middle.


Thanks,
RW