The Gee Spot - You Finally Found It

[Jon]

The answer to the wattage issue is canopy depth. More watts mean that you have to move the plants away, but you get more space back at the bottom of the canopy.

I use an easy rule of thumb. The top of the canopy can only handle 1000-1200 umols, and you need 500 at the bottom. And with widely dispersed LEDs, you lose about 1/2 of your intensity at twice the distance. It's been measured and it's pretty consistent. So, as the math turns out ... if you need 14" of headroom to get under 1200 umols ... that gives you another 14" until it fades to 500. Your headroom roughly equals your canopy depth. More wattage gives you a deeper effective canopy. If you have 1000 umols at 2 feet of headroom, you'll have 2 feet of canopy.

Your canopy depth = your headroom.

Of course, you also have to be able to run with more headroom to get the deeper canopy - taller ceiling or shorter plants.

And that explains it perfectly! Thanks!

 

[Jon]

The difference could be the par. From my limited knowledge, Par is the spectrum of light and PPFD is the volume of light.

I may be wrong though. I need to learn light.

6 years ago I studied spectrum and settled on a Perfectsun Goliath. This time around spectrum seems to be almost industrially uniform so I tossed in an IR and UV bar.

You’re in great shape. Better than me although my light has IR and UV built in during the 680 watt flower time. Not as good as stand alone lights. What are they specifically? I love the Goliath.

 

[Jon]

Oh I like that! I have 36" of headroom at 1000 and only at 75% light in an 8 foot tent. I could use a 36" canopy. Next grow Im going to have to remove the carbon filter to get the light up another 16".

Yup, that’s what I do. Also if you spend the coin for a GGT, they come with 1’ and 2’ extension pieces for the top. Mine is 5x5x9 cuz of the 2’ extension. Height = freedom = fun. Lol!

 

[Jon]

The difference could be the par. From my limited knowledge, Par is the spectrum of light and PPFD is the volume of light.

I may be wrong though. I need to learn light.

6 years ago I studied spectrum and settled on a Perfectsun Goliath. This time around spectrum seems to be almost industrially uniform so I tossed in an IR and UV bar.

In terms of thinking about it for light placement, the difference between the two is irrelevant. For measuring light on your canopy ppfd and par is the same thing. Look at the choices of screen in your app. The ppfd IS par.

 

[Graytail]

In terms of thinking about it for light placement, the difference between the two is irrelevant. For measuring light on your canopy ppfd and par is the same thing. Look at the choices of screen in your app. The ppfd IS par.

You can use footcandles if you're just reading ratios - the measure doesn't matter - twice is twice, half is half. But current white LEDs have a pretty standard spectrum, so the Lumen/PAR/ppfd ratio isn't as important as it used to be - between various HIDs and blurples, etc.

 

[Gee64]

You’re in great shape. Better than me although my light has IR and UV built in during the 680 watt flower time. Not as good as stand alone lights. What are they specifically? I love the Goliath.

They are

Spider Farmer® 40W UV & IR Supplemental LED Grow Light Bar​

 

[Gee64]

Yup, that’s what I do. Also if you spend the coin for a GGT, they come with 1’ and 2’ extension pieces for the top. Mine is 5x5x9 cuz of the 2’ extension. Height = freedom = fun. Lol!

I have a 5x5x7 GGT with 1 extension to 8'

 

[Graytail]

I was at the leading edge of the mid-wattage LEDs when they were first available, and I made a contact with a Chinese knockoff factory and built these from scratch. They're still performing well, primarily because I bought a crap-ton of them and they run very very cool - there are 4256 individual diodes, heheh.

According to my calculations, I'm getting 195 Lu/W at the boards and 180 at the wall. Total is about 650 watts, and I get 1200 umols at 2 feet.

 

[Graytail]

I was looking over my thread from those days and came across some pertinent info. It's 5 years old, but it has a lot of data about lighting, in general. For science.

Graytail's 4th Perpetual: 4x4 Samsung Panels

 

[Gee64]

I was looking over my thread from those days and came across some pertinent info. It's 5 years old, but it has a lot of data about lighting, in general. For science.

Graytail's 4th Perpetual: 4x4 Samsung Panels

Sweet! Im out and about but will read up on this tonight. Very Cool GT

 

[Graytail]

Heheh, a stoner's perogative, if you don't mind? I've always had an awkward habit of blurting stuff out and I'm too old now - the bag o' fugs is getting really empty ... so anyway ...

I'm just meeting you and I was puffing on the pipe and I imagined what I think so far ...

You strike me as an engineer type of some kind, who has maybe an artistic side hobby - like throwing pots or something. Only in this case it's cultivating and nurturing cannabis plants. Yeah, like orchids with the little mister thingy?, only cannabis. I like people who get all distracted when they see data. I'm a data geek myself. (Lazy grower though)

 

[Gee64]

Heheh, a stoner's perogative, if you don't mind? I've always had an awkward habit of blurting stuff out and I'm too old now - the bag o' fugs is getting really empty ... so anyway ...

I'm just meeting you and I was puffing on the pipe and I imagined what I think so far ...

You strike me as an engineer type of some kind, who has maybe an artistic side hobby - like throwing pots or something. Only in this case it's cultivating and nurturing cannabis plants. Yeah, like orchids with the little mister thingy?, only cannabis. I like people who get all distracted when they see data. I'm a data geek myself. (Lazy grower though)

I grow orchids with a little mister thingy and I DO like data but I don't trust it until I see it in action unless its from a reliable source. Proofs always in the pudding.

 

[Jon]

I have a 5x5x7 GGT with 1 extension to 8'

Nice. Gotta love those extensions. I’ve only had to max my light once - when Bill threw me to the wolves on coco. My plants went nuts before I could blink and I waited way too long to flip and next thing I knew I was tying down Blueberry and Dos Si Dos colas ti keep them from hitting the light. Lol.

Did you spring for a set of the 5’ CFM bars? They’re well worth it I think. Not only do they eliminate hourglassing, they more importantly give you beautiful adjustable (up and down) side bars in all four side of your tent. Fans, support, or whatever, to me it was one of the better $30 I spent.

 

[Jon]

I was at the leading edge of the mid-wattage LEDs when they were first available, and I made a contact with a Chinese knockoff factory and built these from scratch. They're still performing well, primarily because I bought a crap-ton of them and they run very very cool - there are 4256 individual diodes, heheh.

According to my calculations, I'm getting 195 Lu/W at the boards and 180 at the wall. Total is about 650 watts, and I get 1200 umols at 2 feet.

Whoa! Very impressive! Looks like you made them sort of modular too? You could use a set as side lights, or mix and match or whatever? Looks as if you built in awesome flexibility. Nice work.

 

[Gee64]

Here is the inside of the Goliath. There are 4 quadrants to the light board. 2 Drivers per quadrant, 2 faulty quadrants so 4 drivers to replace.

I googled the model number but got no hits. Anyone know where/how to find replacements? Is it even worth it?

 

[Gee64]

Nice. Gotta love those extensions. I’ve only had to max my light once - when Bill threw me to the wolves on coco. My plants went nuts before I could blink and I waited way too long to flip and next thing I knew I was tying down Blueberry and Dos Si Dos colas ti keep them from hitting the light. Lol.

Did you spring for a set of the 5’ CFM bars? They’re well worth it I think. Not only do they eliminate hourglassing, they more importantly give you beautiful adjustable (up and down) side bars in all four side of your tent. Fans, support, or whatever, to me it was one of the better $30 I spent.

No, but now maybe I should

 

[Jon]

Whoa! Very impressive! Looks like you made them sort of modular too? You could use a set as side lights, or mix and match or whatever? Looks as if you built in awesome flexibility. Nice work.

You might salivate at this a little bit @Graytail - these are a few shots of the Fohse OI6, 1200 watt beast. Imho Fohse makes the worlds #1 LEDs, and it’s not even close. Check their site sometime. But my buddy Yoda in Oregon just got 9 of these to compare side by side with 9 of his 1200 watt Gavitas. A greenhouse situation obviously. This beast would be way too big for us in tents. But the Aries….that’s my dream light. They also just came out with an 800 watt bar light for home growers that I think is my next light buy. But get a load of this monster.

 

[Jon]

Here is the inside of the Goliath. There are 4 quadrants to the light board. 2 Drivers per quadrant, 2 faulty quadrants so 4 drivers to replace.

I googled the model number but got no hits. Anyone know where/how to find replacements? Is it even worth it?

OMG. I had no idea they were made like that. No offense, but that design makes no sense. Two drivers to replace for each quad? Come on. I’m very surprised. You are experiencing the downside of this design. Yeah, if you can’t just plunk down coin for a new light it would be worth it if you can find them or something comparable. Doesn’t have to be the same, just the same specs.

 

[Graytail]

Yeah, that looks pretty easy! Go on 'baba and look for a 700ma constant current driver that can deliver 65-100 volts. I didn't look but I'd guess less than $15US apiece?

 

[013]

dont know beans about building a light but I think I’d check out meanwell for replacement driver

Mr. Graytail is fast on the draw