[McKush]

Hi all -

This thread is dedicated to the Cycloptics Greenbeams 315w fixture with either bulb 930 or 942. I couldnt find any GB threads when i searched so im starting one for owners and anyone interested in the fixture. Anything related to specifically the GB fixture and bulb is welcome. For discussion of the bulb go to Rives excellent thread which has tons of info and is geared towards DIYers.

https://www.icmag.com/ic/showthread.php?t=299165 .

Im using a Phillips 942 220v (200-277v model) GB over a 3x3 tray in a room just a tad wider 38"x45" and serves as my veg room. I use jacks+calcnit in ro/di water @ 600ppm both in flower and veg. I feed with a timer and recirculate the run off.

Here is Cycloptics site but many vendors carry them. They are a tad pricey $530 to my door but they are also the tits too so ya gotta factor that into the price. Seriously though the reflector is specifically designed for the bulb to give its output a very even distribution with hardly any hot spots and it is also made in the USA.

https://www.cycloptics.com/greenbeams

Here is my GB in use

[Tactical Farmer]

At what distance above canopy can the 315 cmh be set without causing damage I wonder ?

[McKush]

That I do not know at this time, I don't think I've burned anything yet and I've run 28" to 36 or so... I'm hoping to elicit that discussion, input anyone? I am also interested in knowing what height is ok for seedlings with a GB and what the working distances are

[Scrappy-doo]

Great thread!

People been sleeping on these units cause they're set in their ways. Cycloptics hoods are a complete game changer and imo are superior to anything else on the market. The light itself is impressive but the fixture is what makes these so special.

As far as canopy distance goes it depends on the type of reflective material used and the distance from bulb to walls. Using orca or flat white paint diffuses the light and would allow you to get closer. Since the spread of light utilyzes wall reflection primarily, simply widening the space also will allow you to bring the bulb closer if you wanted. but the more you lower it the less efficient it becomes because you lose penetration from lack of angle in side reflection. The strategy for these lights isn't about how close you bring the bulb, it's how well you place relative to your room size. Bit of adjusting mentally to get out of the old lighting paradigm.

[milkyjoe]

So say a 20 ft wide room. Do you need more lights near the center of the room due to less wall reflection? Guess it is best to let Cycloptics model the room for you

[Scrappy-doo]

Yeah if you don't have a wall close to the light on one side you need another light to overlap and create that angular penetration.

I didn't use cycloptics modeling because they have you mount them on top of the ceiling several feet away from canopy. I used 3 lights very effectively in a 5x10 space hanging 30" above the canopy. By their model I would have needed twice as many lights for that space if not more, making the argument for better efficiency fall flat on it's face.

Remember Flip from Cycloptics is not a grower and models the room based on mathematics. But talking to him on the phone, he wasn't able to give me any real concrete answers on how I should set the room up because admittedly, he doesn't know what's best and what works aside from how it looks on paper. Best he could do was point me toward some college studies that were done. We are the real pioneers and will figure what's ideal through trial and error. My money is on hanging reflectors at the optimal distance rather than fixing them above the roof of your flower room. That's just wasting electricity afaic.

[timmur]

Originally Posted by milkyjoe

So say a 20 ft wide room. Do you need more lights near the center of the room due to less wall reflection? Guess it is best to let Cycloptics model the room for you

Hey milkyjoe, follow this link for a room that Beta Test team modeled. It doesn't directly answer your question, but you should be able to get the general idea. Also follow this link for an approximation of the lights you'll need for that space given a target PPF. You're right though, you should use their modeling service and then buy a light meter to confirm/dial it in.

[milkyjoe]

Thanks timmur and Scrappy

[smile]

Scrappy,

With fixtures 30" above the plants what size plants did you grow?

Lower buds were ok and not too fluffy?

Thanks

[Avinash.miles]

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