Get a Harvest Every 2 Weeks

[Enigma]

I'm still considering getting foylon which is 95% reflective but that's gonna be pricy.Maybe I'll upgrade to that after a grow or two.

Any other suggestions aesthetically?



And how much CFM will I lose running a fan through a filter?

Not sure.. but when mine comes in I will test the blow-thru and suck-thru to see which works best.. some say one way, some say the other.. it really comes down to design of the fan and the fluid dynamics of the setup.

 

[Kuji]

I have a question about the 50w per sqft. rule. Earlier you said that you get around 61w p/sqft, but you have two lights over four trays. Each tray is 16 square ft so with one light over each pair of trays so wouldn't you get around 31 wats per square foot since one light covers two trays?

What am no getting here.

 

[Kaosisglobal]

ha Ha that was because he got high.

 

[Al B. Fuct]

Also, this is my rough sketch for my new growroom. It is based on Al's SOG model, and it will be a freestanding room inside a buddy's garage.

I will construct the room out of 2x4's and plywood. I decided to put a wall between the flowering area and the rest of the room in order to decrease the amount of air I have to move, and to increase reflectivity. I will also line the walls of the flowering and mothering area with foylon.

In the space above the clonebox (about 5 or so feet), I am going to have a storage cabinet for all my growing supplies, so the room will be a completely self contained weed factory. I might even put a replica of Al's DIY Bud Dryer in there too so I'll never have to leave.

Oh, and ANY SUGGESTIONS ARE MORE THAN WELCOME!!! If any of you see a way to improve this operation in the space provide, please feel free to tell me!

heh, all looks great. You'll want to swap your cooltube fan direction to blow through the cooltubes rather than suck. Drawing heated air unnecessarily over the fan motor would... well.. suck. The fan motor needs cooling air, too. If it is at the head rather than the tail, the fan motor will run cooler.

Is there another material I could use that would be more suited for my setup?

I was thinking of using sheet rock, but I figured that if I cut a piece out of it and used it as a door that it would break apart at the hinges. Is sheet rock strurdy enough to be used as a door?

Plywood is OK as long as you can keep it protected from spills. If your op's humidity is high enough to damage ordinary underlayment grade ply, it's too damn humid! Your op's RH should be running 30-50%.

Plywood-only doors will tend to warp even in ordinary humidity, so frame the door up in 2x4 or something and skin it with plywood.

I'm still considering getting foylon which is 95% reflective but that's gonna be pricy.Maybe I'll upgrade to that after a grow or two.

Any other suggestions aesthetically?

Foylon's interesting stuff. I haven't seen it locally as yet. They make some interesting sales claims. Would like to see those claims tested (by one of us, thanks), but they seem confident that it is both visible and infrared reflective and even recommend it to stop heat loss through greenhouse floors. Fascinating, Captain.

And how much CFM will I lose running a fan through a filter?

If it's an axial fan- most of it. Axials are not suitable for use with filters. Pick a centrifugal for that job.

I have a question about the 50w per sqft. rule. Earlier you said that you get around 61w p/sqft, but you have two lights over four trays. Each tray is 16 square ft so with one light over each pair of trays so wouldn't you get around 31 wats per square foot since one light covers two trays?

What am no getting here.

You haven't read through to the part of the thread where I worked out that my trays are actually 820mm^2 or 2'8" something and not 4' square. I am not accustomed to use of feet & inches and simply misestimated when I wrote the lead post in the thread.

ha Ha that was because he got high.

Well, that too, but isn't that a given? This is a cannabis forum, fer fuck's sake.

 

[MajesticWhelk]

Foylon's interesting stuff. I haven't seen it locally as yet. They make some interesting sales claims. Would like to see those claims tested (by one of us, thanks), but they seem confident that it is both visible and infrared reflective and even recommend it to stop heat loss through greenhouse floors. Fascinating, Captain.

I've read subcool's growroom 101 thread and he swears by it.

If it's an axial fan- most of it. Axials are not suitable for use with filters. Pick a centrifugal for that job.

Would an inline fan count as a centrifugal fan? Axials are just computer fans, correct?


Edit:
Also, is there an advantage of having 4 3x3 hydro trays rather than two 3x6's? I've crunched some numbers and it seems that I'll be saving a lot of money getting the larger trays.

 

[We TaRdED]

Would an inline fan count as a centrifugal fan? Axials are just computer fans, correct?

correct, but not all inline fans are centrifugal though.

this is not a centrifugal inline fan NGW EcoPlus 4" Inline Duct Air Booster Fan - eBay (item 280221775315 end time Apr-29-08 19:12:27 PDT)




this is a centrigugal inline fan 4" High Output Can-Fan Inline Duct Fan 178 CFM - eBay (item 120112602770 end time May-17-08 17:49:28 PDT)

 

[Al B. Fuct]

Axial fans are distinguished by having a relatively small number of paddle-like blades with wide gaps between them:



Centrifugal blowers have a large number of smaller blades and very small gaps:



Centrifugal blowers tend to move less volume but can deliver high pressure, for a fan, that is- perhaps 2-3psi- they are not air compressors. However, they can push air into high static pressure loads caused by obstructions such as carbon filters, long ducts (more than about 3-4m) or ducts with more than a couple 90 deg bends.

When axial fans encounter high static pressure, air pressure just leaks backward between the gaps in the blades. The CFM rating of an axial is useless if it is pushing into a high static pressure.

Axials are OK for short duct runs with no filters and also as intake fans for a room with a centrif on the exhaust. Since you should be running your room at slightly negative pressure to keep scents from leaking from gaps in the room construction, axials are sufficient. Just use an axial rated at about 80-90% the CFM rating of the exhaust.

 

[Al B. Fuct]

Also, is there an advantage of having 4 3x3 hydro trays rather than two 3x6's? I've crunched some numbers and it seems that I'll be saving a lot of money getting the larger trays.

Yep, having 4 separate trays & tanks allows you to do stuff like dose wk 5 plants with PK-13-14 for 1 wk only without dosing all the other plants sharing their tank.

I use 125L tanks for each tray. Seems a good size as the plants eat the nutes at about the same rate as they suck up the water, keeping nute strengh close to constant even as water level drops. I would expect to get the same result in 3x6 trays, you'd need 250L tanks. Inexpensive storage tubs at the dollar shop don't get much larger than 125L, but those rarely cost more than $20. If you want bigger, you'll be paying a good bit more. Connecting a couple of smaller tanks gets complex. Been there, done that...

 

[VictorVIcious]

I'm still considering getting foylon which is 95% reflective but that's gonna be pricy.Maybe I'll upgrade to that after a grow or two.

Any other suggestions aesthetically?

I noticed a few things. One is the number of doors. Skip the doors, seperate the areas with panda film curtains. You will save your self a lot of money if you view this as an area needing to be insulated, like you would insulate any living space. Forget the plywood, it isnt necessary. You can install Styrofoam or any other closed cell formula product on the outside of the 2x4 wall you construct, put batts of insulation between the 2 x 4's and install panda film as your inside moisture barrier. Unless you are going to pull a permit and make it living space you will not need plywood or drywall on the inside, those are for fire retardation in occupied spaces. This makes it easier for any changes you have to make in your electric and plumbing systems, you don't have a wall to have to cut holes in. Cut a little flap out of the panda film and staple it above all of you recepticles, let it hang down over them, its not waterproof, it will stop spray from hitting them. VV

 

[Enigma]

I noticed a few things. One is the number of doors. Skip the doors, seperate the areas with panda film curtains. You will save your self a lot of money if you view this as an area needing to be insulated, like you would insulate any living space. Forget the plywood, it isnt necessary. You can install Styrofoam or any other closed cell formula product on the outside of the 2x4 wall you construct, put batts of insulation between the 2 x 4's and install panda film as your inside moisture barrier. Unless you are going to pull a permit and make it living space you will not need plywood or drywall on the inside, those are for fire retardation in occupied spaces. This makes it easier for any changes you have to make in your electric and plumbing systems, you don't have a wall to have to cut holes in. Cut a little flap out of the panda film and staple it above all of you recepticles, let it hang down over them, its not waterproof, it will stop spray from hitting them. VV

I agree the panda film for the doors.

The only problem is.. if they want this thing to last, the plywood painted with flat white latex paint would be the best option for durability.

E

 

[MajesticWhelk]

I was thinking of just putting up the frame and lining it with visqueen, but this is going to be a permanent structure. I also hear that it is difficult to make a lightproof seal with panda film alone.

I don't mind cutting a few holes if it means better stability and reliability.

 

[MajesticWhelk]

AHHH I'M SO MAD I DON'T HAVE MONEY!!!

Check out this deal:
3 x 1000Watt Grow Lights+ Entire GROW FOR SALE

 

[Al B. Fuct]

I was thinking of just putting up the frame and lining it with visqueen, but this is going to be a permanent structure.

For many years, my rooms were simply hanging curtains of panda film attached to a lightweight rectangular timber frame screwed to the ceiling.

I also hear that it is difficult to make a lightproof seal with panda film alone.

nah, dead easy. Just overlap a couple inches where joins have to be made and glue it with silicone sealant. Use tape to temporarily hold the pandafilm together until the silicone sets up.

 

[VictorVIcious]

To make it a more permenent structure you would put the plywood on the outside, and it wouldn't need to be plywood, it could be osb. If you think you can seal plywood better than you can seal air leaks in styrofoam.....I'm done. VV

 

[Al B. Fuct]

osb?

My latest room is my most permanent to date- framed up with 2x4s and skinned with 3mm MDF, interior wrapped with a single run of pandafilm. The entry is still a bit tent-like, reminiscent of my old rooms, with a flap of pandafilm just behind the door. I didn't attempt to seal my room. Since it runs at slightly negative pressure, any air leakage from my wonky constructions is going down the exhaust duct.

 

[cmak40]

I was thinking of just putting up the frame and lining it with visqueen, but this is going to be a permanent structure. I also hear that it is difficult to make a lightproof seal with panda film alone.

I don't mind cutting a few holes if it means better stability and reliability.

IF THIS IS PERMANENT. spend the money on pressure treated wood. and yes you can light proof an are with panda film me and al have both been fruitful in doing so....... and i didnt mean to seal the room for moisture with the panda film but rather air sealed for stink reasons and he wont have to paint if he did that

first one is the pressure treated frame work, second is the panda film sealed room after, and then the PANDA film sealed mother area

 

[VictorVIcious]

If you seal the outside of the room so no air leaks in, it won't leak out either. If the plywood were necessary on an inside wall all of the houses in the country would be falling down. Thats a nice room you have. VV

 

[Kuji]

You haven't read through to the part of the thread where I worked out that my trays are actually 820mm^2 or 2'8" something and not 4' square. I am not accustomed to use of feet & inches and simply misestimated when I wrote the lead post in the thread.

Sorry about that. So that means a 600w 90k HPS falls well short of ideal for a 4' by 4' area ( about1200mm^2) and provides an average amount of light for a 3' by 3' area?

Do you think I could get away with a 600w over a 4' by 4'?

 

[Al B. Fuct]

If you seal the outside of the room so no air leaks in, it won't leak out either.

Very true. However, in my case, I'm just a shithouse carpenter and lucky things stick together or stay apart... I'm hugely lucky if all I get is a few small air leaks instead of a breeze...

If the plywood were necessary on an inside wall all of the houses in the country would be falling down.

Agreed.

I skinned my 2x4 framed room with MDF to make it look from the outside like something other than a frame with a pandafilm grow tent inside. Appearance only. Makes it look like a storage closet. Visitors who are none the wiser remain none the wiser.

 

[Al B. Fuct]

Sorry about that.

No, I'm sorry for not measuring it before quoting the figure!

So that means a 600w 90k HPS falls well short of ideal for a 4' by 4' area ( about1200mm^2) and provides an average amount of light for a 3' by 3' area?

Do you think I could get away with a 600w over a 4' by 4'?

You'd grow plants, for sure, but I think you may begin to get somewhat ordinary production on the fringe of the light coverage with a 600 over 4x4. It would be on the lower end of what I might suggest for a 4x4 table.

You could move plants around often to even out growth, but I think the result would be just to spread out the reduction in yield/density across the entire batch, sort of what happens with light movers.

You can always just not pack the table full to the edges of the light coverage if you don't get the density you want.