250w hps in small area

I have a question about hps, I am working in a small space and I really want to upgrade the cfl to hps. I found a great tutorial on making a cool-tube from a 4" pyrex bake-a-round and plan on using this for cooling the bulb. My question is if I purchase a 4" inline fan/filter combo with 170cfm would that be enough air flow to cool a 250hps? Or am I underestimating the cooling power of the inline fan, could I go 400hps in this area?

BTW- I'm running 6 23w cfl's and depending on ambient temp the grow space temp fluctuates between 75 and 89 degrees.

Bump, Anyone?

I could use some advice thanks!

This is exactly what i want to do, i have an area 18"x36"x36" that i want to try this on. From the people that i have talked to, it should stay cool with a 4" inline. My temps now with 4-27w and 2-42w CFLs are around 78 degrees.....

even if you are cooling the bulb, if you have it too close to your plants they will burn. about 12 inches clearance from the tops of the plants should be acceptable.

https://www.rollitup.org/indoor-growing/323608-my-first-grow-w-pics.html

got any more pics of the cab? it looks nice. how tall is your box?

You could put 250 watts in there. But you would also need some excellent ventilation given the small space.

LimitLimit said:

This is exactly what i want to do, i have an area 18"x36"x36" that i want to try this on. From the people that i have talked to, it should stay cool with a 4" inline. My temps now with 4-27w and 2-42w CFLs are around 78 degrees.....

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That's what I'm thinking Limit, everything I've found says that 4" should do the trick. Thanks for the post.

purplecream said:

got any more pics of the cab? it looks nice. how tall is your box?

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Thanks purplecream, I have a couple more but my images aren't working right now. It's a sterilite cabinet 25.63Lx18.87Wx69.38" from target. Cost around $90. I have some posts of it if you search for sterilite you should be able to find it. I seperated it into a mother, cloning area and flowering. The biggest issue I had with it is all of the light leaks.

HydroHutGuy said:

even if you are cooling the bulb, if you have it too close to your plants they will burn. about 12 inches clearance from the tops of the plants should be acceptable.

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Hey hydrohutguy, I've been doing a LOT of research and I am pretty confident that I can keep the heat under control with my diy cool tube. I just recieved my bake-a-round from ebay and as soon as I save 120 bucks a 250hps is mine. I think I could get as close as 4" if not right on top of them. Thanks for the post bro.

swelchjohn said:

You could put 250 watts in there. But you would also need some excellent ventilation given the small space.

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I hear that swelchjohn, that's what I got the bake-a-round for. I'm unsure about the size fan though. The ones I've been looking at on HTG are affordable but only 170 cfm. I'm not to sure that it'll cut it.

Peace

you can definitely put a 250 watt in there. i suggest a cooltube tho.

ive used a self made cooltube with pyrex bake-a-round things before. honestly, its kinda pointless with 250 watts. sure, they get hot, but dont worry about the cooltube, just increase the overall ventilation. heat rises, extract the rising air rapidly and you don't have to worry about the rest. you lose a small amount of light through the glass, and the benefit is that you get to put it slightly closer to the plant, which just negates the loss caused by the glass. here's what i'd do (and what i have done, after realizing that cooltubes on 250w lights isn't worth it): add a fan to blow between the plants and the light. increase overall ventilation. K.I.S.S.

I currently run 4x 600w lights, and my plants sometimes get as close as 4 inches away with no negative effects. i have an airflow between the light and the plant, and way more ventilation than is necessary for the space i'm in. imo cooltubes are more for removing heat from sealed grow spaces, not ventilated ones. also dont put 400w in that space, it's overkill, splurge on the fan instead.

My box is 3'x3'x4'. It is completely sealed except for the 4" intake and exhaust holes. I havent started yet but am running a 400 HPS. I am just testing everything out to make sure its gonna work how I want. My temps, with 135 cfm fans and the temp gauge at 6" below hood, are 85. You should be fine.

^^ thanks for the info you just saved me money! i was gonna buy a cooltube.

Well, I do run the 400 inside a cool tube. Its got the 4" inline fan pulling air though it too cool off the bulb. Go with the cool tube if you are concerned. If I didnt have it, the temps would be way to hot. Even behind the tempered glass, its 85 max at 6" under lights. About 80 at 12" under.

I use a 250 watt hps in a small cabinet...temps run at 75* with no cooltube. check out the link in my sig......

Thanks for all the feedback everyone, I just ordered a 250w MH/HPS Digital from Ebay.
It includes the yo-yo's, reflector, both bulbs, electronic ballast, socket, timer and shipping for $150.

Thanks again!

Now for the cooling I'm looking at upgrading to this fan/filter combo.
Does anyone have an opinion on these units or a better solution for a 4" fan/filter?

Thanks.

HydroHutGuy said:

even if you are cooling the bulb, if you have it too close to your plants they will burn. about 12 inches clearance from the tops of the plants should be acceptable.

https://www.rollitup.org/indoor-growing/323608-my-first-grow-w-pics.html

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That would depend on which of the wattage lights he went with, that if that was already decided and I missed it … ignore the rest. If he went with the 250-watt CoolTube with adequate light ventilation he could run that light right down just a tad off the plant tops.

When I used to grow with 250-watt lights I would try to keep them roughly 6 to 8 inches off the plant tops but 4 or less inches happened now and then and I seldom cooked anything and if I did it was minimal. A 250-watt does not put off all that much heat, yes way more than a CFL, but compared to higher wattage HID lighting, they run cool and even with a standard reflector you can run them pretty close.

You have to run them close because they only give off about 18 inches of decent light so if you hang it a foot over your plant tops you wasted one foot of your best light and only 8 inches, roughly, of your plant top is receiving decent light and the rest is in a low light situation.

You should not need a foot of space between a 400-watt CoolTube and the tops of your plants if the air movement to cool your light is adequate, but it would have to be a fair bit farther than a 250-watt light would .. and much closer to fitting what you said than a 250-watt light would be.

That is not meant in any way as an endorsement or suggestion to go with a 250-watt light.

I always say if you can use higher wattage, unless you are going into overkill, like trying to pull off a 1000-watt CoolTube in a computer case grow, pick the higher wattage. You do not have to go for it all but if you are trying to decide between a 150-watt light and a 250-watt light, pick the 250-watt light and if between a 250-watt light and a 400-watt, pick the 400-watt … and then if a 400-watt and a 600-watt .. again always pick the higher unless it is a case of overkill, you have more than surpassed you system needs to consistently supply a yield that always covers your needs.

Thanks Brick Top, I have decided to go with the 250 mh/hps.

I am going to start a scrog for the second time with some bagseed to work out any kinks in the system. The information I have gathered all pointed to a 250 with the space that I am working with. It's 24w X 18l x 48h. With some ingenuity, I will fit the 250 in the bake-a-round ducted out to a 4" 190cfm vortex fan & carbon filter. The attached picture illustrates what I am working with. The florescent unit in the bottom flowering area will be moved to the top mother/cloning area and the hid w/ cooltube will be mounted in the bottom flowering area. Then I will begin scrog-ing clones to start my perpetual grow.

Any opinions please?

how did that 250 mh/hps work out for you im looking to maybe get one of those as well