So I got temporary a t8 power glo that puts off 18000k but it doesn’t look that bright. I also bought a 17 watt actinic bulb for night for my anemones until my other light system comes in. Don’t know what else to do.
"Brightness" is a human eye construct.
And so is lumens..
That particular bulb emits 750 lumens
(Search hagen lighting guide)
"Daylight" bulbs of the same wattage produce way more lumens. 1470 per Hagen.
Not sure why they list yours as bright except that it's brighter to corals..
Lumen measurements center around the visually bright green range and downplay the red and blue ranges .
Point us it should be brighter to plants/corals than it is to you.