Anybody use a two 48” utility shelf’s thick piece of plywood and a flood table in a gorilla 4x8 to nearly double yield potential?

outopotme

Active Member
So apparently I got a cut back a little bit and get rid of one of my 4 x 8 so compromise. Why don’t I just have basically 2 in in one tent? I’m calling it the double decker. Anyone ever do this and have any tips let me know. I plan on using two 720’s for the top shelf/table and under since the shelves will cut the bottom by 18” on each side, putting a scorpion Diablo right in that little extra space under neath. Fortunately my ceiling is tall enough for the 2ft extension but unfortunately 9 ft is as tall as she’ll go for me. 5’ for each level, maybe one day.

thoughts?
 

Apalchen

Well-Known Member
I’ve yet to see even large facilities be able to pull off the same amount of weight per sq ft of canopy. That being said your canopy is doubled with stacking so you can yield more while hitting less per sq ft of canopy. So maybe scale back on the lights a bit to something that can be kept closer to the canopy. I’d ditch the quantum board fixture idea unless you already have it, strips would be better with how close your gonna need to be to canopy.

Airflow is the other big hurdle, for people going vertical, even in large rooms with tons of fans and hvac units they have trouble with climate pockets. Not saying it’s impossible but just be mindful of it in your design and try a few different fan layouts.

It’s a fun idea and I have been debating it for a while myself, when I get a new veg room I might convert my old one into a two tiered led grow. I would have room for 2 4x8 double decker tables with plenty of room to move around them.
 

MedicinalMyA$$

Well-Known Member
I tried this in a 4x4, biggest issues were airflow, access, and spillage. Had to mount the can and fan externally. I ended up cutting an extra hole in the side of the tent, using a ducting splitter, and pushing the air through the filter instead of sucking it through.

Spillage was another issue, even using a large tray with large sides. As the canopy grew it became quite tight in there and mistakes were made and stuff got spilled. Water would travel along the edges of the shelf and along the underside to drip from there onto the lower section lights and plants.
I solved this by making a large poly 'tablecloth' over the shelf where the overhang would act like a drip edge and direct any spillage down the sides. Made a watering can extension using a bit of hose and a bamboo plant stake for extra reach too, this was originally to help with watering the upper level without spilling any but was actually more use on the lower level as due to the height and access restrictions it was a on the hands and knees job.

Thought about an automated irrigation system but the drama that would ensue if anything went wrong made it not worth the risk. Accidental flooding would be catastrophic, and adjusting drippers etc on your hands and knees at the back of a 4x4 tent under a low canopy while trying not to damage any plants or lights is a big no from me.

Also I mounted the drivers externally to help with heat management and height arrangements. With the lights so close to their respective ceilings the drivers would get hot, which then required cooling/directed airflow, which was difficult because of space issues, so outside of the tent they went. That was OK for me as I DIY my lights, but for pre-made lights you might need to purchase and assemble driver extension cables etc...

There isn't much room for circulation fans, even those small clip-on models. I went with no fans, and relied on the air exchange from inlets and outlets placed at opposite sides of the tent instead. Worked for me but surely won't for all circumstances. Lucky for you, you have a 9ft height so it might not be a problem especially if you manage your canopy accordingly.

Overall it was a lot of effort and mistake making and experimentation, there is probably a lot more I'm forgetting right now, and yield was pretty much doubled due to twice the canopy, but I ended up with a lot of stuff outside the tent which ate into the space I thought I was saving.

Planning ahead would help, even to placement of cables and multi-boxes in relation to access doors. I found that nearly everything I had tidily arranged out of the way was a royal pain in the ass to get to. Re-setting the surge protector on a multi-box neatly tied to the far left tent pole on the bottom level while reaching between canopy, light, and other stuff while on your hands and knees halfway into a wet tray and tent comes to mind. It's the little things that become annoying to do that end up being delayed or ignored that wind up hurting your yield (I'll do it tomorrow...)

Done a few runs with this setup but ended up going to vertical canopies, which is far superior IMO. No airflow issues, room to move (stand), more canopy/actual grow area, and less issues all around.
 

ilovereggae

Well-Known Member
I tried this in a 4x4, biggest issues were airflow, access, and spillage. Had to mount the can and fan externally. I ended up cutting an extra hole in the side of the tent, using a ducting splitter, and pushing the air through the filter instead of sucking it through.

Spillage was another issue, even using a large tray with large sides. As the canopy grew it became quite tight in there and mistakes were made and stuff got spilled. Water would travel along the edges of the shelf and along the underside to drip from there onto the lower section lights and plants.
I solved this by making a large poly 'tablecloth' over the shelf where the overhang would act like a drip edge and direct any spillage down the sides. Made a watering can extension using a bit of hose and a bamboo plant stake for extra reach too, this was originally to help with watering the upper level without spilling any but was actually more use on the lower level as due to the height and access restrictions it was a on the hands and knees job.

Thought about an automated irrigation system but the drama that would ensue if anything went wrong made it not worth the risk. Accidental flooding would be catastrophic, and adjusting drippers etc on your hands and knees at the back of a 4x4 tent under a low canopy while trying not to damage any plants or lights is a big no from me.

Also I mounted the drivers externally to help with heat management and height arrangements. With the lights so close to their respective ceilings the drivers would get hot, which then required cooling/directed airflow, which was difficult because of space issues, so outside of the tent they went. That was OK for me as I DIY my lights, but for pre-made lights you might need to purchase and assemble driver extension cables etc...

There isn't much room for circulation fans, even those small clip-on models. I went with no fans, and relied on the air exchange from inlets and outlets placed at opposite sides of the tent instead. Worked for me but surely won't for all circumstances. Lucky for you, you have a 9ft height so it might not be a problem especially if you manage your canopy accordingly.

Overall it was a lot of effort and mistake making and experimentation, there is probably a lot more I'm forgetting right now, and yield was pretty much doubled due to twice the canopy, but I ended up with a lot of stuff outside the tent which ate into the space I thought I was saving.

Planning ahead would help, even to placement of cables and multi-boxes in relation to access doors. I found that nearly everything I had tidily arranged out of the way was a royal pain in the ass to get to. Re-setting the surge protector on a multi-box neatly tied to the far left tent pole on the bottom level while reaching between canopy, light, and other stuff while on your hands and knees halfway into a wet tray and tent comes to mind. It's the little things that become annoying to do that end up being delayed or ignored that wind up hurting your yield (I'll do it tomorrow...)

Done a few runs with this setup but ended up going to vertical canopies, which is far superior IMO. No airflow issues, room to move (stand), more canopy/actual grow area, and less issues all around.
I second this. More trouble than it's worth.

Make sure if you do it that the lights mounted on the lower shelfs are totally waterproof.

Humidity spikes and airflow are the 2 biggest issues.

If I had a warehouse or large greenhouse with 12 foot ceilings I would do it without question.

In a tent I do not think it's worth the effort.

I wound up just getting rid of my dresser and 1/2 my clothes and making space for another tent.
 

Apostatize

Well-Known Member
not exactly what you're doing but i've been playing around with the idea of squeezing a 2-level grow ~8' tall. But I was thinking of having bloom on top and veg on bottom. perpetual. but it will be a few years, not months, before I upgrade to warehouse shelving. i'm thinking of setting up 3 of them, not 1. 1 would be cool, though.

bloom space/height i'm not too worried about, i feel like i've worked most of that out. really close to lights without burning.

on the first level (veg) (less than 4'), i'm thinking i'd use fewer of the same size lights (66" Fluence Rays, they also have a 44"), ballasts with ~1/2 the amps as I use for bloom, dimmers, and mounting twice as many lights for veg as i'd have on at any time (e.g., 4 mounted, but have the veg 16-18 hrs divided into 3 hrs at a time where lights 1 and 3, then 2 and 4 are lit. plenty of fans, but that's easy.

was thinking the base of the top shelf had to jut out wider than the bottom shelf area so there's no light leakage, plus panda paper or some kind of screen i can pull down. and hand-feed to avoid most of the overflow/spillage. access: currently, i can walk around 3 sides; that's helpful.
 
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