Is the Seneye fairly accurate at the lower and higher ends of the spectrum? I've read that some meters fail at reading something like 450nm and below and 660nm and above leading to readings that are lower than they should be.
funny thing.. It's sensitivity is equiv. to the "old" Apogee 200 series but in practice (numerous discussion and comparisons on reef tanks against Li-Cor and the new 500 series) the "errors" don't really show.
Now if one had a hort. lit tank (heavy 660,430) it is very possible it is quite off..
Apparently the overshoot in high red compensates for undershooting the low red..
Sad too because it is just a bad choice of a high pass cut-off filter..