Growing with 720w LED in Soil Feeding/water methods.

Ahlarza · Aug 21, 2023

Hello Everyone,
This is my first time posting and I have a few questions about growing under LED.
My Experience: Almost 2 yrs (noob), 3k sqft rooms, 28 Gavita 1000w HPS light.
I'm currently testing at home a 660w LED I bought from a grow store and notice method of growing is different.

This is my current set up.
Light: 1x GrowPro HM660w (720 boost) LED
Medium: Sunshine #4 Soil.
Pot size: 5x gallon
Nutrient: 5 gallons of House and Garden Grow and Bloom Powder + Cal Mag + Si + H2O2.
Co2: Small Tank
Strain: Wedding Caking + 4 unknows
Current Veg/Flower Stage: 4th week of Veg from Clone

I notice my feeding/watering schedule is different from HPS. I fed my veg every 4 to 5 days even at the 4th week. They are about 2.5-3ft tall now from a 8 inch clone. Top 4x and FIM 4x.
I actually watered maybe 2 time out of 4 weeks of veg, I lost track of feeding and watering until I notice later... No deficiency or burn.

My Feeding data

2gram per gal of H&G Grow
1gram per gal of H&G Bloom
2gram per gal of Cal-Mag
1ml per gal of Si
Faucet Water PPM = 120
Total PPM = ~700-800 Max
PH = 6.4-6.5
Run off PH = 6.4-6.6*
Temp is 85f-93f during the DAY and night is 78-80f...it is my garage at a corner. I'm not allow to grow inside the house, lol.
Co2: Haven't use this yet until flowering.
H2o2 was used only twice during the time of watering.

My questions/concern is, I notice feeding schedule is totally different from HPS and LED. My dry-back is quicker with HPS and LED seem to take a while for the soil to dry, even if the room is +85f.
Do plant overall drink less when growing with LED and require more feeding interval than watering? I saw YT video from Dr. Bruce Buybee, that they only FEED their plants through out the whole stage and the time they had to water it, was when the EC,PH,PPM was off (testing purpose).

I guess I got lucky I didn't experience any burn with feeding back to back in a 4-5 day interval and PH was within spec. The only time I feed it, is when I notice the soil was between Moist and Dry. I'm surprise with the room so hot, 85-93f, dry back is fairly long within the temperate range...

Overall, I was wondering if anyone here has experience with grown using High wattage LED in the commercial field or at home, using soil. I am planning to switch over my HPS to LED in the near future if I feel confident using LED.

Trash_2002 · Aug 21, 2023

Ahlarza said:
Hello Everyone,
This is my first time posting and I have a few questions about growing under LED.
My Experience: Almost 2 yrs (noob), 3k sqft rooms, 28 Gavita 1000w HPS light.
I'm currently testing at home a 660w LED I bought from a grow store and notice method of growing is different.

This is my current set up.
Light: 1x GrowPro HM660w (720 boost) LED
Medium: Sunshine #4 Soil.
Pot size: 5x gallon
Nutrient: 5 gallons of House and Garden Grow and Bloom Powder + Cal Mag + Si + H2O2.
Co2: Small Tank
Strain: Wedding Caking + 4 unknows
Current Veg/Flower Stage: 4th week of Veg from Clone

I notice my feeding/watering schedule is different from HPS. I fed my veg every 4 to 5 days even at the 4th week. They are about 2.5-3ft tall now from a 8 inch clone. Top 4x and FIM 4x.
I actually watered maybe 2 time out of 4 weeks of veg, I lost track of feeding and watering until I notice later... No deficiency or burn.

My Feeding data

2gram per gal of H&G Grow
1gram per gal of H&G Bloom
2gram per gal of Cal-Mag
1ml per gal of Si
Faucet Water PPM = 120
Total PPM = ~700-800 Max
PH = 6.4-6.5
Run off PH = 6.4-6.6*
Temp is 85f-93f during the DAY and night is 78-80f...it is my garage at a corner. I'm not allow to grow inside the house, lol.
Co2: Haven't use this yet until flowering.
H2o2 was used only twice during the time of watering.

My questions/concern is, I notice feeding schedule is totally different from HPS and LED. My dry-back is quicker with HPS and LED seem to take a while for the soil to dry, even if the room is +85f.
Do plant overall drink less when growing with LED and require more feeding interval than watering? I saw YT video from Dr. Bruce Buybee, that they only FEED their plants through out the whole stage and the time they had to water it, was when the EC,PH,PPM was off (testing purpose).

I guess I got lucky I didn't experience any burn with feeding back to back in a 4-5 day interval and PH was within spec. The only time I feed it, is when I notice the soil was between Moist and Dry. I'm surprise with the room so hot, 85-93f, dry back is fairly long within the temperate range...

Overall, I was wondering if anyone here has experience with grown using High wattage LED in the commercial field or at home, using soil. I am planning to switch over my HPS to LED in the near future if I feel confident using LED.

I made the switch from hps to led some months ago, did one cycle and almost 20 days flower on the second one atm, 645w flexstar lm301 diodes bars.

Yes plants under led transpire less even with higher air temps. Also they transpire less beacause we need higher RH running leds together with the higher air temp for plants to be happy.

Fabric pots help, I'm now using them 6gal, and I got the drybacks to 3-4 days between feedings (50/50 peat/perlite) before the fabric pots it was around 5 days to dry back properly.

Getting RH right seems to be very important with LEDs plants early flower don't like lower than 50% RH at all, 60-65% they like.

LEDs uses less energy to push out more light, BUT you have to spend a bit more on environment control than with hps, more dehumidifier power, setup humidifiers schedule if needed and depending on location also heaters.

Another thing light burn is a real thing with leds, those bars are freaking strong, have to be on top of it to prevent lights damage and also Mg, CA and K deficiencies, a good RH seems to be the ticket to control nutrients uptake and prevent the dreaded LEDs deficiencies, it's easier to control vpd with leds but you need a better environment control overall too, if that makes any sense. Lol

Ahlarza · Aug 23, 2023

So it looks like ill need more dehumidifier If I plant to switch over to LED for a 800sqft room. I have a 600cfm exhaust and 15 fans and 1 Quest 502 Dehumidifier.
I wonder if that would be enough to control Humidity in the room using LED.
Before you switched over to fabric pots, after the 5day dry back, did you feed again or water instead?

Winter here is going to suck, its below freezing sometime. The last guy that grew in the same room, he said HPS made it easy during the winter, lol.
I keep on hearing people struggle during the winter with LED, especially at Dark Time: High humidity.

Trash_2002 · Aug 24, 2023

Ahlarza said:
So it looks like ill need more dehumidifier If I plant to switch over to LED for a 800sqft room. I have a 600cfm exhaust and 15 fans and 1 Quest 502 Dehumidifier.
I wonder if that would be enough to control Humidity in the room using LED.
Before you switched over to fabric pots, after the 5day dry back, did you feed again or water instead?

Winter here is going to suck, its below freezing sometime. The last guy that grew in the same room, he said HPS made it easy during the winter, lol.
I keep on hearing people struggle during the winter with LED, especially at Dark Time: High humidity.

Sorry missed that post as I wasn't quoted neither marked, I always feed every watering peat/perlite 50/50

You need a dehumidifier that can take all the water that goes in.
If you give your plants 100L per week you need a dehumidifier that can take out true 100L/week, plants transpire ~90% of what goes in + evaporation from media, so a little bit overpowered dehumi will do the job with easy.

Ahlarza · Aug 26, 2023

Trash_2002 said:
Sorry missed that post as I wasn't quoted neither marked, I always feed every watering peat/perlite 50/50

You need a dehumidifier that can take all the water that goes in.
If you give your plants 100L per week you need a dehumidifier that can take out true 100L/week, plants transpire ~90% of what goes in + evaporation from media, so a little bit overpowered dehumi will do the job with easy.

I have a 250gal water tank. I'm not sure how much water will be needed PER week with LED, but it looks like maybe 250-500gal per week. I guess ill have to figure that out soon. But base you stated, it might be enough, 502pint Dehumidifier. I'll have 256 plants in total for 32 LED, so 8 plant per light. My last run, I was able to only yield 64lb at 85-90% power setting on the 1000w HPS. I know a guys that yield the 85-93lb using the same LED light that I bought, GroPro 660w. He's still dialing in his room. He doe share what he learnt, but told me to take it with a grain of salt, because he's still dialing in it. He has 3 110p dehum. and never had PM issue, but only running 192 plant for 32 LED lights, and he's yet to experience the winter trail period as well. Hopefully my fan set up allows proper air circulation towards the dehum. Fans are set up to blow towards one fan to make a circulator flow TOWARDS the dehumidifier. And I have 6 fan in the center oscillating. So far no PM, but again, HPS dries the room well.

Thanks for the info Trash_2002 !!

Growing with 720w LED in Soil Feeding/water methods.

Growing with 720w LED in Soil Feeding/water methods.

Ahlarza

Trash_2002

Ahlarza

Trash_2002

Ahlarza

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