Abstract: The monolithic hybrid LED array includes a metal heat sink substrate, a ceramic layer on the substrate, and a plurality of series-connected epitaxially-formed LEDs connected by interconnects such as conductive ink strips. The array preferably includes three to six sets of series-connected LEDs that are tightly packed on the substrate. The LEDs are housed in a modular housing having a power regulating circuit and an override feature for overriding the regulator to produce the maximum LED output for brief periods of time. The regulator may continuously vary the light intensity output from the equivalent of 0 to 2000 micromols per second per meter squared.