1000w DE HPS I average 2-3 pounds per/light depending on genetics
Growers Choice 720 I averaged 1.5 pounds on 2 runs one with AutoPots and one with normal pots
Mars Hydro TSW-2000 when I first started trying LEDs I was getting 6-8 ounces per/light and I believe the true wattage on those is 350w...
1000w DE HPS results
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Mars Hydro TSW-2000 results.
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Growers Choice ROI-720 results:
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Hard to say whats going on but you should be able to yield more from a 5x5 with 720w; 1.5 pounds is what we can usually squeeze out of a 4x3.
It could be the autopots; ive not tried them myself but read some growers stating problems with them keeping the media too wet.
As for growers choice: as far as me goes its not the greatest nor the worst, dont trust their numbers completely unless i see an independent light lab report. You should be able to do better with those watts. It might be better suited to a fuller cannopy cause then you can push it down towards the cannopy and really use all the light.
Some things you can try:
- go back to basics with growing technique; run to waste coco seems to work very well with leds as long as you prebuffer the coco and really keep a sharp eye on the plants already in vegg: if they start protesting light intensity with bleachy, mag deffy growth you can try even higher temps. Redo your calculations for vpd:
https://vpdchart.com/
It will come out differently depending on difference between air temp and leaf temp. Also remember that vpd is only part of the equation: CO2 will close the stomata which means you need to push a bit higher vpd. Also blue and uv may also help open the stomata. But in the end You also need the heat for the metabolism. Really the main thing is getting your plants into flower in a super healthy state and up the intensity progressively and when they can really take just push as much light as you can.
- play around with light factors: fill the cannopy better and look into whats missing from the spectrum: far red and uv. Before dingying your lights you could see what happens if you add a bit of far red and uv. I know kingbrite on alibaba have a few good and cheap options here. This also lets you try it out on one light to see the difference.
- if you have a feeling that your space might still not be hott enough for perfect growth try adding a horticulture heating pad under one plant.
Before digging more money into lights id look into these things.
Top lights on the market seems to be the HLG Scorpion, quite expensive, growlights australias High Lights 420 v2 boards and maybe Fohse if you have the height. But youd really need to see if youve actually hit your highest possible numbers with the lights you got right now before any of those lights will change the situation in a mayor way.
And if you wanna go down the rabbit hole just look into diying the light youd really want.