[Red Bear]

Opinions wanted.
16x20x8ft. 6tons of air conditioning.
Will this work with 3 ft of space between bulb and canopy?
12 gavitas at 1kw.
Low ceiling height is the concern, is 6 tons of cooling the answer?

[Speed of green]

6 tons is fine.

i stole this from another site but i agree with the recommendation.


A common problem i see with the DE fixtures is that people dont have the correct distance from canopy to light fixture. I seemed to find best results with this little reference i made up:

(Distance from canopy to bulb) (Light Spread) (Wattage Output)
(@ 2') (5'x4') (600-660 Watts)
(@ 2.5') (5.5' x 4.5') (660-750 Watts)
(@ 3') ( 6' x 5') (750-825 Watts)
(@ 3.5') (6.5'x5.25') (825-1000 Watts)
(@ 4' ) (7' x 5.5') (1000-1150 Watts)

Ive been messing around with the height differential and best wattage used. also helped determine a realistic canopy spread. This little chart^ isnt saying that you should butt up your spread of light side to side. Gavitas work best with cross lighting so overlapping the spread is definitely recommended. I feel that 3'-4' of canopy height is needed when running at 1000W. IMHO its over kill of light in to tight of light spread. Ive seen negative affects @ 2'-2.5' of canopy height, raising the lights helped, so does training and trellising
run your fixtures side by side not end to end. This utilizes the cross lighting too.

[Red Bear]

Thanks speed of green!

Anyone have any ideas on how to arrange the lights?
I have 9 3x6 trays. Room is now only gonna be 12x20x8ft. Side by side yes, maybe 3 rows of 4 like 1.25 lights per tray?

I need advice on co2 for that size of room,

And size of dehumidifier?
Please if anyone has run a room like this?

Drain to waste Rockwool.

Thanks

[Speed of green]

along each 20' wall place three trays, then another row of three trays down the center. this will leave you a 1.5' walkway.

4 lights over each row.

The room may be a bit small for 12 DE's

[Red Bear]

Thanknyou again speed of green!

Sounds right, maybe only 10 DE.

could use dehuey advice, 155 Quest?

And co2 advice, burner or tanks?

I REALLY appreciate any responses.
Maybe if I upload pics I will get more advice?

[Speed of green]

a 4 burner co2 should work fine, you would run through bottles like crazy in that room

i think 12 750's would be better, can you dial back the 1000wDE?

i worry with the 1000's you wont be able to take advantage of the whole footprint.

if you go 4 lights per row, starting at the end of the row you would hang a light every 3' 7" on center

155 quest should be fine.

[Red Bear]

Thank you!
Speed of green, your the only help I have gotten on this site and on this issue and i greatly appreciate it, you rock!

I can dial back the phantom d.e with the px1 controller.

Burners are new to me...

So are sealed rooms, any tips?

[Red Bear]

Oh yeah, went phantom D.E. saved a grand on 10 lights over gavitas

[Speed of green]

High temp shutoff is a must
keep everything clean
dont procrastinate on trellising/training
if its possible try to put your trays on wheels, working through 4' of dense canopy will kill your back.

make sure all the fittings on your co2 burner are tight and not leaking, otherwise propane will leak out and kill your crop, ask me how i know

make sure you build the room out of safe materials that do not off-gas.


pretty generic advice, not necessarily specific to sealed rooms.

Whats your growing medium?

Watering schedule?

plant count?

[5lrootsexcel]

If you only have an 8' ceiling, I would recommend just putting them on the ground the trays. The phantom de has the stupid 90* ballast design so you're going to lose 6" from the ballast alone leaving you with 7.5 feet. 7' after you take into account the 6" cube (I'm assuming you're going to use 6" cubes). That leaves you with a plant height of 3-4' so flip at 1.5' ish so don't veg too long.

I think a quest 155 might be pushing it depending on your plant count and how often you're watering.