Optimal plant height for a SCROG with Citizen 1812 ?

Planning my next grow and this is gonna be my 1st full grow with cobs. Growing in Flogro 500, EBB&Flow. I have 2 bars of 3 citizen 1812 3000K CRI80 driven @ 1.05A each, and was thinking of doing a scrog with 2 clones in a 3x3 tent.

But what's the optimal height when in full flowering to still get good penetration with those leds and not end up with too much (if any) lollipop buds ? And what's the optimal distance between canopy and leds ?

a scrog starts at 8-12inches anything higher is a support/trellis net.But to answer your question, when there are half the height you want them at apply a net.