This arrived this morning - an Apogee Instruments MQ-650 with the ePAR sensors that measures radiation from 380-760nm (as opposed to most sensors that 'see' 400-700nm.) The sensor will measure PPFD from all light sources, including LEDs (but will be useful for measuring PAR from light sources that produce UV and Far-red radiation, such as metal halides). This meter automatically corrects for the immersion effect. It will be interesting to get some measurements under my belt. More ASAP.