Just so I understand.. how is that possible that 1152 LED spread over a 2x2 area (or aprox for the hlg 550) have a lower spread than a single light point in a HPS light?
I just feel its the same debate over and over again but results are there.. hps you will get from 0.5 to 1 g/w and with quality LED (not talking about blurple here) you get 1 to 2 g/w..
In fact 650-700w in a 4x4 is all you need to get 1000ppfd at any place over all your canopy if you use something like strips (which use same led than quantum board) which would match a DE HPS.. so 500-550w quantum should get you pretty close to a 1000w SE HPS
You dont believe in LED thats fine but no need to disinform everyone looking for good advice on their next light.
There has been already a few side by side done but lets be realistic.. in 10 yrs from now we will still have the same debate because its almost impossible to do 2 grow exactly the same way.. and then compare results.. so unless you prove me there is a significant difference between HLG-550 and a 1000w HPS The total Lumen output is about the same keeping in mind that the hps is 360 degrees and loosing light power off the reflection
Thats just my 2 cents! LED for the win