Hi, This is the link to my grow journal thread which I posted in the wrong section. Apologies for that. Could a mod move it to here if possible? http://forum.grasscity.com/absolute-beginners/979562-first-attempt-250w-scrog-barneys-farm-lsd.html I would love to hear some feedback! Thanks.
Hi need some advice please. Just got a 600w bulb and ballast on loan and was wondering could slot it right in or would it be too much for the space. What distance should I maintain betweem the bulb and the canopy top? Thanks in advance.
I'm giving it back tonight and getting a loan of a 400w hps and ballast instead. I think that will suit better for the box's dimensions?
Hi Phyking, I hope I can give you the info you wanted! Dimensions: Box = 4' x 4' x 4'6'' Screen = 25'' x 26'' Floor to Screen = 2' Screen to top of canopy = 7'' Light is about 7 or 8 inches from top at the moment Temps: Inside: 15c (57f) -> 23c (73f) Ambient (Attic) 6c (43f) -> 13c (55f) Fans: *120mm 30cfm intake in floor sucking from downstairs (Ambient is a bit higher than attic) *120mm 30cfm exhaust fan blowing through ceiling of box, into cardboard box with carbon cooker sheet on top (replacing lid of box) Kind regards, BombScare
Well you don't need an intake fan for one, so just use both fans for exhaust. I wouldn't set them on top of each other just do them side by side or on opposite sides at the top, and just have a free intake somewhere near the bottom, make it a little smaller than the combined space in the holes for the fans so you get a negative pressure. But for a 400w hps I think you will have to get a better fan, specially when you're in flower and you need to add a carbon filter. Are your ambient temps 55 degs constantly? If they are then you could get by with a cheap fan
I did consider using both fans beside each other for exhaust but the reason I decided to go with an intake was to encourage more of the warmer air from downstairs to rise up in and therefore reducing the amount of work the heater has to do to maintain temps. What would be the benefit of switching to both exhausting? I think you are right about needing a better fan if the 400 goes in. I was offered a 150mm centrifugal fan and an odorsok to match but I thought it might be too much and not allow the heater to keep the inside temps high enough. Any opinions? My attic temps range from 43-55. Thanks.
Well if your ambient temps are that cool then I would deff throw some more lights in there, if you're using cfl's that is. But the 400 might work just fine, go to the growroom and design section and go to the ventilation thread and use the heat formula that's a hyperlink on the first post. Using that you can determine what fan you'll need if any
Cheers for that phyking, a worthwhile thread to read. The 400w HPS is now in at 11'' from canopy. Oscillating fan on highest setting now. I think I am ok for CO2 replacement once temps are ok. Will monitor temps for now and see how she progresses !