LED vs HPS? No-brainer. HPS is inferior and there are no arguments yet to contest that.
How many watts? I’d
build LED fixtures that will at-least match, but may outperform 1000w HPS DE fixtures. I’ve designed one that costs less than $750. You can buy a timber light or one of the other high-end fixtures if you want, but you won’t have the luxury of designing your space around the exact specifications of your fixture. Your initial investment will also be nearly doubled.
The closest Timber LED fixture to my design for a 4’x4’ space is the
Redwood CS 4’x4’ (which is a very new product of theirs btw)running you $1,399.00 per fixture. This produces 1420 μmol/s (
PPF) and 953 μmol/s (
PPFD - covering a 4’x4’ space).
Now if you built your own fixtures, you could do 9x Vero 29 SE Gen 7 3000k COBs running @ 38.7 voltage x 2.1 amperage producing 81.27 watts per diode bringing the total power draw to 731.43 watts encased within a 3’x3’ fixture if you wish or even 4’x4’; it depends on other factors. The PPF for this fixture would be 1647.018 μmol/s with a 4’x4’ PPFD of 1105.381. Half the price of buying from a high-end manufacturer with 14.8038% more usable light output. Only difference being the Redwood TS 4’x4’ claims to achieve its light output with 600 watts while mine draws around 730…But, we must remember its best to assume the numbers advertised by a manufacturer pushing their product are probably skewed a bit. Its also important to note that the pictures Timber uses for their fixtures aren’t always the exact product they’re advertising to be sold (I’ve confirmed this myself) so you’d want to take that into consideration as well when considering the validity of the numbers they advertise.
For 40 “very large plants”, I’d consider 2 plants per fixture. So, 14,628.60 watts total (20 fixtures). People are approaching 2 GPW (Gramps Per Watt) with LED these days. I’d put everything I own on there being someone out there running a room @ 2 GPW consistently with LED. @ 1.2 GPW you’d be just barely under a L per plant (0.979lbs – to be exact). So a 40lb harvest…Which is dependent upon many other factors of-course such as the ability to maintain optimal RH (Relative Humidity), optimal ambient temperatures, adequate ventilation, stabilized fire genetics, substrate system type, nutrients, CO2 supplementation, etc., throughout the entire course of your growing cycle.
The price isn’t low because I cut corners btw. Every component is of the highest quality available. My fixture even uses the exact same heat sinks as Timber’s, which are considered to be the best on the market currently and the dude that produces them is a cool guy. Its also a highly efficient COB LED relative to other designs.
Solis Tek’s 1000 watt HPS DE advertises >2,000 μmol/s meaning 1342.28 PPFD for a 4’x4’ space. Problem is, bulb degradation. Its been tested that the light out put of this bulb is reduced by 28% after 3 months of 12/12 use. So initial output is >2000 PPF and after 3 months you’re at 1440 PPF. Initial PPF if you built out my design, 1647.018 μmol/s with minimal degradation. You want big plants, your cycle is going to be at-least 3 months, testing would be required to determine when HPS’ light output becomes inferior to the LED fixture. Maybe do the community a favor and acquire some meters to collect/post that data for us
