Does anyone use a light meter to measure the light output in their terrariums? I think I need to boost my light a bit..... I'm getting readings around 7000 lux at the top of an 18" tall and 1200 lux near the bottom....seems very low to me.
We've used a lightmeter from Amazon to measure light output.
Does look like you could do with increasing the light; We get 1000-1200fc (so around 10k-12k lux) at the top by the light, 600-800fc (so around 6k-8k lux) in the middle, and 400-600fc (so 4k-6k lux) at the base of the tank. That's with a Jungle Hobbies advanced LED light.
That light looks very cheap, and given that it doesn't mention its lux output, I'm not surprised the plants aren't doing so well.
We've been impressed with the JH Adv LED - in fact, it was a little too bright for some plants; our restrepias took a while to adjust and we had to move Lepanthopsis astrophora 'Stalky' out because his leaves were purple. But everything else is loving it and thriving (mainly phals).
Although more expensive, a PAR meter that measures light intensity in the “photosynthetically active range” is better to assess what your LEDs are delivering to the leaves. It matters whether your LEDs are producing diffuse light or whether the light is focused at all. There would be different PAR requirements for low light, medium light, and high light orchids. Day length will also matter, depending on the type of orchids you are growing.
An advantage of growing different genera with different light requirements is that you learn by experience the intensity of light without a lightmeter.
You won't have accurate readings but it will be enough.