Is it because the closer the walls are to the light the more light is reflected off the walls, therefore a loss in intensity.
Almost, but a very good guees! I think what’s happening is the walls are actually not reflecting all of the light energy, like absorbing some of the energy and converting it to heat.
If so, what conclusions could be drawn about the placement of light?
As close as possible turned down to achieve the proper DLI
Ya, at least drawing conclusion that a light can be too high. As justified by not intentionally bouncing light off walls when not necessary.
For what it’s worth, should also be noted that hlg qb-135 kits came with a 120 watt cv/cc driver that ran at max output. The patriot ships with 200 watt constant power driver that is ran less than it’s capable output. My qb 135 pulled 129 watts from wall, not 150 like the mars light. When talking about lights running in the neighborhood of 2.5 umol/joule 20 watts is 50ppf increase if all else is equal. In 2x2 increase of 50 ppf incrases ppfd average by 135 umols/s.
Bought a LUX meter to measure the outputs. My HLG 350R is 50% (or more) better than the viper Spectra V1200. Upgraded in time to hit the flowers coming out of veg.
That is actually surprising to me bc i believe the viper 1200 is equivalent to 520 watt, or almost 200 more then 350r
Yeah i really like my marshydros but as mentioned above they drop off on the edges hard on the umols and ppfd. I had 2 ts3000’s in my 4x8 and still had a big light gap in the middle so at the time i got the smallest light they had which i believe in the 100 to cover my gap. If i had another chance id go thru a different manufacturer but like dbrn said if its not broke its not really justified for a bit better performance
Here’s the DLI chart I use. Hasn’t steered me wrong yet. Screenshot it last year on here. I don’t know who posted it but thank you for sharing it!!!
Blew my mind. The VP1200 draws 565watt. the HLG350R, 335watts. I will recheck this weekend.
These readings are from 30 inches below the lights. Clearly the 350 runs cooler (and more now, since giving it a cooling fan directed at heat sink fins. All results bear re-checking and distance manipulation, as i get comfortable with operational changes.
Love my 350r’s. I get a little fox tailing even at 280w. Imo 900 ppfd is the max you wanna give with those.
At 30 inches (for now), is easily achieved.
Cant chance burning precious flowers.
Operating 350 in the range of 40-70%, monitoring or timing dependent.
Still awaiting the AC-ADL8 Type B cnx UIS dongle, for 69P control of dimmer operations.
Watching and playing in the zone of 40,000-60,000 lux, distance will get adjusting soon.
Yes, I just ran the numbers on HLG charts. Looks like I could get closer and turn down the driver to 50%,
We have colder and wetter weather coming next week.
Works well for me too.
15-20 inch available canopy, as set currently. Can’t go lower and still enter tent, unless crawling.
Tallest/shortest plants good in the 15-20’ zone.
Tent temps reduced with lower settings and cooler outdoors comming.
@Poseidon1 Thanks for the words and numbers.