[cenamus]

From skimming Wikipedia it seems like most absorption happens in the blue range and a bit less in red, almost nothing inbetween at green. Most LEDs are blue with a phosphor, so you usually get more blue light than the rest already.

But surely there are LEDs optimised for that task (Cannabis grow lights)

[ash_091]

There are LEDs optimised for that purpose. Not strictly necessary though.

Someone I know had a very successful indoor cannabis grow using nothing but a cool white outdoor LED panel light from the local hardware store.