How many umols are too many? 1200 umols too much? LED's with red or no red?

I am working with someone who has a room about 11.5 feet wide and 16 feet long. 4x12 in trays on each side with a 18" row down the middle. About 4 feet in the back for dehumidifier and fans.

The setup would had six - 1000 watt HPS with three on each side. It did very well. Perfect set up but the heat and power usage was too much.

He moved to one HPS, four QBs 600-H's, 1 PathrX (red diodes & more powerful than QBs) and a Spider Farmer 4000 (like QB's 600-H but with red diodes). The HPS is to keep the room warm.

My guy is saying that the room was way over 1200 umol. Maybe 1400 umols. He said it is down to about 1200 umol by pulling one QB. The room now has one HPS, 1 QBs, PanthrX and Spider Farmer 4000. And added one 315 Watt LEC in the middle.

He is saying he thinks 800 umols is better?? He screwed up and was not keeping the temps with the lights on at 80 deg F or more. The dude had a killer setup and constantly changes things.

So are QBs with no red diodes good?

Is 1200 umols or 1500 umols too much? Is 800 umols better? Thanks for any help.

800 umols, evenly over the cannopy, is much easier to grow with. 1200-1500 is not only much harder, especially with low temps+leds, it has diminished returns and its much harder to keep plants happy.

1500 umols is for CO2 supplementary grows.
edit:
your friend needs to understand at some point C3 plants will get capped by CO2 then all extra luminosity wont make a difference at all, just increasing temps & transpiration

Kassiopeija said:

1500 umols is for CO2 supplementary grows.
edit:
your friend needs to understand at some point C3 plants will get capped by CO2 then all extra luminosity wont make a difference at all, just increasing temps & transpiration

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So you need to have the CO2 going to push 1200 to 1500 umols? He had that running and was saving money by not refilling propane tank.

Colo MMJ said:

1200

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with normal atmospheric CO2 levels thats too much... you also need to increase temps... a CO2 setup actually needs to be dialed well in - closed & climate controlled.

My mate ran the numbers - 24 inches - umols.

PanthrX & HLG 600-H QB - 2300 umols
HPS SE 1000 Watt 8"Hydrofarm - 2100 umols
Spider Farmer 4000 - 2050 umols

Impressive numbers from HLG at 600 watts because PanthrX is a pretty big light.

Colo MMJ said:

My mate ran the numbers - 24 inches - umols.

PanthrX & HLG 600-H QB - 2300 umols
HPS SE 1000 Watt 8"Hydrofarm - 2100 umols
Spider Farmer 4000 - 2050 umols

Impressive numbers from HLG at 600 watts because PanthrX is a pretty big light.

Click to expand...

Is that just the centre reading of each light?