Good to know about the distance from source to sensor. I'll test at 12 inches in order to standardize. When I started doing light measurements back in the early 90's, I used a distance of 3.5" since most luminaires rested on the aquarium's top and this was the distance from source to water surface. Times have changed... Matt @BoomCorals - I'm testing the Kessil AP700 now. This will get involved when considering multiple spectral/intensity settings. Thanks again for your support!Please post up. 12in in air is a really good median base line to judge a lamp imo.
It's how I do it at shows, lfs and home but with a lux meter.