Testing began this morning on the referenced luminaire. Initial impression is very positive. With the luminaire six inches above the water surface, and at a depth of 17" (total of 23" from light to improved MQ-510 PAR sensor) PPFD can over 300 (light at maximum intensity.) PUR, as measured by a Seneye device, is a respectable 76%. I've got to do a ton of work with this light, but so far, so good.