HLG 600 Rspec with UVA bar

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MrChillz

New Member
Hello everyone new here and introducing myself along with trying to understand some issues I'm having during my flowering stage. I've been growing for years and very familiar with plant needs and ph parameters, humidity levels, temperature ranges. I've just started using an Led light, this is my 3rd grow with LEDs and have been experiencing problems 2-3 weeks into flower. I began familiarizing myself with VPD and the different RH/Temperatures LED lights require but still running into problems. The light is approximately 30 inches from the canopy and my PAR reading are with 600 -750 spread across a 4x4 tent. I'm growing in soil, Promix to be exact and using the FoxFarms full line of nutrients. I'm supplementing with CalMag usually twice a week about 15mg over a weeks time. In my last 3 grows I keep running into what looks like a CalMag difeicency about 2-3 weeks into flower after the flip. I'm running the room at 81°F with a RH of about 60-65%. At this point with all the years of growing experience I've had I just can't seem to understand why I run into problems with these lights. Maybe I'm not feeding enough? Maybe the LST isn't right? Maybe my PH is off? My pH run off is always less than 6.8 and sometimes I fluctuate it. I'm always going in at 6.5ph sometimes 6.6. The only thing I'm missing is supplemented C02. The symptoms start on the older fan leaves first and then gradually start moving onto the newer leaves. Any ideas what could be my issue? Any intelligent and educated options please share!
 

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Nutty sKunK

Nutty sKunK

Well-Known Member
MrChillz said:
Hello everyone new here and introducing myself along with trying to understand some issues I'm having during my flowering stage. I've been growing for years and very familiar with plant needs and ph parameters, humidity levels, temperature ranges. I've just started using an Led light, this is my 3rd grow with LEDs and have been experiencing problems 2-3 weeks into flower. I began familiarizing myself with VPD and the different RH/Temperatures LED lights require but still running into problems. The light is approximately 30 inches from the canopy and my PAR reading are with 600 -750 spread across a 4x4 tent. I'm growing in soil, Promix to be exact and using the FoxFarms full line of nutrients. I'm supplementing with CalMag usually twice a week about 15mg over a weeks time. In my last 3 grows I keep running into what looks like a CalMag difeicency about 2-3 weeks into flower after the flip. I'm running the room at 81°F with a RH of about 60-65%. At this point with all the years of growing experience I've had I just can't seem to understand why I run into problems with these lights. Maybe I'm not feeding enough? Maybe the LST isn't right? Maybe my PH is off? My pH run off is always less than 6.8 and sometimes I fluctuate it. I'm always going in at 6.5ph sometimes 6.6. The only thing I'm missing is supplemented C02. The symptoms start on the older fan leaves first and then gradually start moving onto the newer leaves. Any ideas what could be my issue? Any intelligent and educated options please share!
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Looks like a calcium def. question is, why?

When I tried running LEDs I needed more calcium. It’s to do with LST (Leaf surface temp)

Although the room was 27c the leaf surface temp was 23c. This slows down the movement of calcium. Maybe Co2 was needed? Not sure.

Adding more calmag helped stop the deficiencies. I ended up using twice as much as under a HID lamp. I do have very soft water tho. Is your water source soft or hard?

So I switched back to HID lamps which gave a much better leaf surface temp. 26c air and leaf temp. No cal issues since.

So in your situation either add more calmag or increase ambient temps.

Good luck!
 
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MrChillz

New Member
Thanks for the reply. I viewed my local water authorities report and they are showing no calcium in the water. It's hard to believe with all the CalMag I'm adding that there could be a deficiency but I am running ProMix and this median has essentially 0 nutrients. I've read that the perlite doesn't hold calcium well? I'll try to keep adding 5 mg/gal every water and feed.

My LST does reach 82°F/27.7°C with ambient air temperatures around the same or a degree higher but comes down after the tent is exhausted. Could it be the temperature fluctuations? Maybe I need to increase humidity to 70%?

I own 3 different Ph testers and after recalibrating them all, the Ph is always different between all the testers.. not by much though maybe 6.55 compared to another might read 6.63.

I'm to the point where I'm thinking of changing my nutrient lineup. Maybe FoxFarms just isn't up to date with this LED lights I wonder.
 

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