Trying to answer "How many (and type) LEDs to use my 70 gal?" or simply, "Is 24 XPG enough? 36?"
I've been estimating with spreadsheet V.3.
Tank: 48wx18dx20h, 3" substrate
Frame: 1.5" aluminum extrusions, 3 x 48" rails on 5.25" centers.
Table for PAR est. for L,M,H light (see below)
LED height: Tank_height + LED_Height_above_water - Substrate_depth
Conditional format: 1) PAR background is blue, green, orange for L,M,H light. 2) current background is red when >rating.
Table for Spread with LED_Height and Cone_Angle
I'm not clear about how the "rows" work. I'm trying the geometric mean of LED_spacing and my LED_row_spacing.
Trying to validate the calculations, I ran across 84212-designing-building-led-fixture-22.html#post1102937
... and the spreadsheet isn't coming close to real world observations.