Need advise on new Grow Cabinet - 400W HPS - Pics Included

Hello my fellow RIU members,

I have done a successful couple of grows in my PCs, yet due to my inability to utterly conceal the light and some heat issues I have decided to scrap my PCs all together and move up to a cabinet. The box is done and will double as a fish tank holder. The inside dimensions are 32Lx19Dx32H. I have concealed up all the leaking light on the front and sides and now I am just awaiting the staining process before I begin to do the inside set up.

I will be running a 400W HPS in a cooltube with one 120mm [70-80cfm] intake and one exact same fans as an exhaust hooked up to the cooltube. This leads me to my first few questions which are; Will this be enough "fanage" to keep the bulb fairly cool? Next, my cooltube is 6in and my fans are 4in so can I get 6in ducting and tape it to the 4in ducting to connect it to my fans?

To finish up the ventilation I have two more 120mm [exact specs], one for intake into the chamber and one for exhaust into a carbon filter. I will, also, have a small osculating fan to blow over the canopy/light inside the cabinet.

Furthermore, I will be running DWC hydro in a 12.5 gallon tub. My next question is how many plants would be optimum for this amount of space? With the low amount of vertical spacing I know I will have to ScroG and/or LST. After minusing the hydro tub there is about 17-18 inches before you hit the cooltube. My last question would be how far do I need to set my ScroG screen up above the hydro tub? I was thinking 10in at first, but then thought that 7-5in would be better because that would allow 10-12 inches for the bud to upwards. I have a marker on one of my pics where 10in, 7in, and 5in would be too.

Thanks in advance for the time and advise. This bad boy should be up and running real soon

-X

Edit-That blue fan will not be hanging there after the inside set up. It is merely there to cool the light while I was calking and light testing.

Damn dude, that is a fairly tiny space to be using a 400W HPS! How are the temps in there? Your cooltube doesn't appear to be hooked up to anything?

Anyone willing to read before they post? Anyone?

Nice little cabinet bro, but I seriously doubt those fans are going to help your temps much with a 400 in such a small space... They put out quite a bit of heat.

id say two to four but damn thats confined

Right on guys, I appreciate it. I still have a couple of unanswered questions if anyone is interested. I sure hope I can keep these temps down, but if not I think I will return the 400 for a 250 which should drop my heat a bit.

-X

get yourself a solar palau td100 inline fan and you will be able to keep that light cool through the 4in reducer

You could also try a 265cfm Hydrofarm blower with 6" intake flange (sold seperate). It keeps my 400 watter nice and cool. You would have to mount on the outside, but you would with any other high powered fan you try and put in there. Id make a stealth box with holes in it covering the fan. Good luck.

Thanks guys I will keep those brands in mind. I figured I would have to replace at least a fan or two just because of the low cfm ratings. I am going to continue to test the temps after I stain the cabinet and I will go from there for the ventilation.

Anyone have any suggestions on how many plants or how high I should place my ScroG?

Thanks again,
Xander

Xander said:

Hello my fellow RIU members,

I have done a successful couple of grows in my PCs, yet due to my inability to utterly conceal the light and some heat issues I have decided to scrap my PCs all together and move up to a cabinet. The box is done and will double as a fish tank holder. The inside dimensions are 32Lx19Dx32H. I have concealed up all the leaking light on the front and sides and now I am just awaiting the staining process before I begin to do the inside set up.

I will be running a 400W HPS in a cooltube with one 120mm [70-80cfm] intake and one exact same fans as an exhaust hooked up to the cooltube. This leads me to my first few questions which are; Will this be enough "fanage" to keep the bulb fairly cool? Next, my cooltube is 6in and my fans are 4in so can I get 6in ducting and tape it to the 4in ducting to connect it to my fans?

To finish up the ventilation I have two more 120mm [exact specs], one for intake into the chamber and one for exhaust into a carbon filter. I will, also, have a small osculating fan to blow over the canopy/light inside the cabinet.

Furthermore, I will be running DWC hydro in a 12.5 gallon tub. My next question is how many plants would be optimum for this amount of space? With the low amount of vertical spacing I know I will have to ScroG and/or LST. After minusing the hydro tub there is about 17-18 inches before you hit the cooltube. My last question would be how far do I need to set my ScroG screen up above the hydro tub? I was thinking 10in at first, but then thought that 7-5in would be better because that would allow 10-12 inches for the bud to upwards. I have a marker on one of my pics where 10in, 7in, and 5in would be too.

Thanks in advance for the time and advise. This bad boy should be up and running real soon

-X

Edit-That blue fan will not be hanging there after the inside set up. It is merely there to cool the light while I was calking and light testing.

Click to expand...

1) Unless you have constant AC into that cabinet, no, 2 120mm PC fans will not work. I have a 400CFM sucking through my 400HPS cooltube and its very hard to keep my temps down (I average mid 80's).

2) 120mm fans are actually bigger than 4". I have 4 120mm fans that fit quite snugly in 6" ducting.

3) I dont do hydro

Thanks for the reply purplehazin. I guess I will have to call HTG tomorrow and see if I can swap it for a 250W because I know I can't get a direct root to AC to blow in. Thanks for the tip on the fans fitting into 6in ducting man, I appreciate it. That is what I will do for sure. Lastly, are you suggesting me not do hydro or just telling me that you don't do it?

Thanks again man,
X

Hey Xan, I'd have to agree that the 400w would be too much in that space. They put out so many lumens that anything within 10 inches of the bulb will just turn white after 24 hours. The 250w will need at least 6 inches gap to the plants for the same reason. I'd choose the middle or bottom level for the screen for that reason.
2 plants in hydro with 4 or 5 weeks veg would easily fill the screen. I'd prolly place them near either end and grow them towards each other.
Why do you want 12.5 gallons for the rez? It seems a lot and using something a little smaller could gain you an extra couple of inches headroom.

Because of the temperature issues you're bound to have with that big light in the small space, I would recommend soil instead of hydro. High rez temps will kill your plants with root rot. You could get away with some nice hempy's in there though.
For a scrog in that space I would put the screen somewhere in the middle, 12-15 inches below the bulb. You may be able to do it a little higher if you have a good fan blowing across the top of the canopy... A good rule of thumb to follow: If you can hold your hand on the top of the canopy for over a minute and it doesn't feel hot, then your plants will be able to handle it. I would also not run more than 2 plants because you're really not gonna have the room for more than that in there.

Thanks dewbzilla and v12, I have in fact taken everyone's advise on the light and temps and called my supplier asking if I could exchange my 400 for a 250. They said to think about it and call them back and after getting your guys input I decided to call them back and tell them to ship me the 250W. This should help with my heat quite a bit. Leading to my next question; does you think I will have any rez heat problems with a 250?

Thanks guys,
X

Hey man, I meant to say I have no experience with hydro, so I couldnt answer the question. Good luck!

I hate found out that my rez temps need to remain in the 65-75F range which I believe is possible with my set up. I might have some altering to do, but I doubt I will have a problem.

v12, I am thinking about cutting three inches off my rez though -would bring it about 6in H and maybe about 10gal ish. This would give me an extra three inches to work with, but is it needed? I can move my light down because I am getting chains so I can always keep it 12in away until it reaches the top. I figure an extra three inches couldn't hurt right?

purplehazin, thanks for checking back. wish I could have kept the ol' 400, but Cheers mate!

-X

Hey Xan, I don't think you can have too much headroom.
To put the hydro into context, you are effectively considering 2 plants in 10 gallons, or 5 gals per plant. In soil 5 gallons will produce substantial plants and hydro allows much more rootspace than soil does. I wouldn't worry about a lack of rootspace in 10 gallons, better to have more space for the buds and a suitable distance from the light to the canopy IMHO.
Under a screen the foliage will prevent much of the heat getting to the rez so you should be ok, you could also use insulation around it to reduce the effects of the heat.

Sweet thanks for the reassurance v12, it is always much needed. Thanks for putting the hydro into perspective. I definitely think your right, as always , and will be removing that excess three inches today. This like you said is unneeded and a bit over kill on the rez. I think I have also decided on 3 plants -two in the back row and one up front. This would purpose 3.3 gal per plant which I am thinking would be best because I really do not want to be vegging for 4-5 weeks. I was thinking of 7-14 days of vegging if any at all. Since, I can not go to far up I think -similar to my pcs- that vegging for a long time would be counter productive. Does any of this seem incorrect or ass backwards for what I am trying to do? All input is welcome and will be appreciated. Thanks.

-X

Sounds like a plan to me mate.