downhill21
Well-Known Member
Dr. Bruce is da pimp
recommended ppfd range?
- Thread starter sunny747
- Start date
Deusracing
Well-Known Member
OK I’ve been trying to jump into this LED game and I got to keep the cost down but I want to keep the yield some of the same. My last grill came in at 4 pounds in a 4 x 8 tent running 1000 white hyper arc HPS. 2 pounds came from one plant the other 2 pounds came from eight plants two per container. No I’ve been looking at the Kavita 900 E because it’s in my price range and I need two of them or I’ve been looking at the California light work solar stream 500 can anyone here give me advice on which one of those two I should choose again I have a 4 x 8 area ceiling height is 6 foot 11
Deusracing
Well-Known Member
OK I’ve been trying to jump into this LED game and I got to keep the cost down but I want to keep the yield some of the same. My last grill came in at 4 pounds in a 4 x 8 tent running 1000 white hyper arc HPS. 2 pounds came from one plant the other 2 pounds came from eight plants two per container. No I’ve been looking at the Kavita 900 E because it’s in my price range and I need two of them or I’ve been looking at the California light work solar stream 500 can anyone here give me advice on which one of those two I should choose again I have a 4 x 8 area ceiling height is 6 foot 11
ComfortCreator
Well-Known Member
If I wanted to do it right in a 4x8 i would get 2 fluence like units (spyder knockoffs) or run QBs or strips across the entire canopy. At 7' vertical you are severely limited in height. Not badly, I work with less than 8' but it limits some light choices. No COBS or high powered QB96s for example.
Dont invent this wheel and dont buy commercial high end. Build or get a high efficiency unit at a good price.
MedicinalMyA$$
Well-Known Member
Out of the two I would go for the Gavita, better spread for your height.
dont think so. check with par meter. u might be surprised.
Deusracing
Well-Known Member
No I try to buy hobbies lights like the gavita 900. I look for lights with 7-800ppfd at 12-18”
Deusracing
Well-Known Member
And I will never buy knock offs. Led are not the same. Even if they say they are. If I invest it’s one and done
ComfortCreator
Well-Known Member
I'm cool w that but you wanted inexpensive!
MedicinalMyA$$
Well-Known Member
4lb in a 4x8 is a pretty good run IMO. LED's take a few runs to acclimate to, you might not be able to reproduce your current results the first time you use them, the plants react a little differently to what you would be used to with HPS. You may have to adjust other environmental factors to get back to your happy place.
ComfortCreator
Well-Known Member
HLG has their 3 board, 320 watt setups on sale for $410 right now.
If you bought 4 and used the riu discount of 10%, you would have 1200+ watts spread across 12 boards and have 4 separate units that can be raised and lowered together or separately. Would be very efficient and cost effective. R-spec spectrum.
Deusracing
Well-Known Member
I suppose o should of put a price range on here. Lol
Deusracing
Well-Known Member
That’s some good info. I did a experiment with one hlg100 on one small plant to see what it does. It ran its whole life in there except last week I moved it under 600w hortilux blue because I needed to take down my 3x3 but here’s my first led grow it gets chopped this week
Deusracing
Well-Known Member
That’s not a bad idea
Deusracing
Well-Known Member
Thanks guys. I appreciate the input.
MedicinalMyA$$
Well-Known Member
What I mean by happy place, is after years of using HPS all I knew was that if I had things in the tent a certain way e.g. temperature, moisture in the air, ventilation, type of hood/reflector etc, then all would go well and i would get very pleasing results. I later leaned this perfect balance of factors was having correct Relative Humidity, Temperature, and Leaf Temperature, and was called Vapor Pressure Deficit or VPD.
After switching to LED it took a while to find the balance again because I had changed the temperature (less heat from the LED), humidity (temperature affecting humidity) and had different leaf temperature (no IR in LED's I was using). So had unwittingly altered the three contributing factors that were for years getting me to my happy place. When I first used LED I didn't change anything and I couldn't routinely get to quite the same level as before so I reverted to HPS until I read up a bit more on LED's, discovered what VPD was and how to implement it, tried LED's again using the new knowledge, and now a few years later am regularly exceeding prior yields.
One big factor for me is the wall to wall spread available using bar-style LED's. I will never go back to single point-source lighting. With the bar-style lights you can dim them down but run them closer to canopy when needed, and still retain proper PPF levels. I build my own lights now using many LED strips run about 6" or less above a flat canopy and peak around 900+ PPF in a 4x4 for about 300W+-ish draw.
TeW33zy
Active Member
No, 500-700. Do not go more than 300 ppfd over ambient otherwise you get hermies and foxtailing. That’s why so many people are getting Hermies, expecially with so many breeders selling seeds that are prone to throw nanners. It’s hard to breed out nanners. Just because you can’t. You can stress test a plant for 1 year then seeds of her can throw nanners. It’s because of different locations, lights and grow environment. You can’t stress test for every environment. LED light is artificial and it’s stressful. Going over 700 ppfd on 350 ambient is risking nanners and terpene volatility. If you want terps reduce your ppfd to 600 to finish the last 2 weeks just to stop terpene volatility. If it’s extremely strong at high light levels you are evaporating them through high light. Stay under 700 if your ambient c02. If you have C02 above 1200-1400 then up your ppfd to 1000 and no more. You don’t need all that light.
Billy the Mountain
Well-Known Member
That's terrible advice.
"300ppfd over ambient" is nonsensical.
~1000 ppfd is widely considered optimal for indoor grows with no C02 supplementation.
Cabrone
Well-Known Member
The way I understand it is they can't absorb more light than 1000 ppfd Without supplement co2.
1000 ppfd is maximum, not optimal? if all other environmental factors are perfect. If the vpd is off, poor air flow high or low temps, humidity levels, all afffect how much light they can absorb without stress? Maybe 600-800 ppfd helps keep your plants from frying if environmental factors are off?
That being said I totally agree 300 ppfd over ambient seems an odd way to figure how much light they can handle?
MedicinalMyA$$
Well-Known Member
My understanding is that after about 1000 PPFD the benefits of adding more light drops off quickly, Law Of Diminishing Returns etc... with supplemental CO2 apparently you can move the peak of the LODR bell curve to 1500 PPFD