Give me your thoughts on this one will you

[Roadblock]

Hey guys I need some ideas ,, I got a room 3x3x2 mtr ,, its only source of of ventilation is 2 x 100ml x 4mtr long pvc pipes , the pipes run straight up ,, the room has aircon and only 2 x 400watts ( clones and mum) .

 

Now I want to have a carbon filter on the intake to catch insects and mold spores in the air .

 

What size fan ? what size filter ? remember it must pull the air 4mtrs down a 100ml tube and through the filter , I was thinking a 150ml fantech but not sure , what do you guys think .

 

Thanks Rod

[everest]

think the fan and filter would have to be bigger than that rod for those dimensions ... i got my filter on the other end too ... my flower room would be similar and i using 2 x 180 alvent fans plus 1x200 alvent pulling in , then a huge 300 pulling it all out .... but it's hot here

 

ev

[Roadblock]

Thanks Ev ,, yeh Im a bit lost on this as I normally just pull heaps and dont have the restrictions I got to deal with on this room , the plus is I dont have a lot of heat with only 2 x 400watts and the aircon keeps that down ,, would I be better running say 2 x 150s in line or go a 200 or 300 with reducer ,, the out vent has a chimney effect but would still need some help I,d reckon .

 

Rod

[everest]

Now I want to have a carbon filter on the intake to catch insects and mold spores in the air .

 

think thats the problem there ... just use some tights , add a oscilating fan to spread the air around in the grow room to keep the mold from starting , then 2x 150 will be good ... big sucker pulling out , so the air exchange is at max

 

ev

[thc24]

ive got a simular size room RB 3x 4m,

 

with a 1x 2m grow room inside with 2 600s, air is exhausted through a 250mm centrifugal fan and filter.

 

air into big room passive 2x 300m holes, passive inlet into grow room is the same 2 x exhaust size= 2x 300mm holes with duct pointed at A/C.

 

ive recently seen a decent idea in a grow shop, a inlet 300mm dia length of duct runs down the centre of grow room with many small holes and blocked at one end, instead of one inlet you now have many smaller spaced evenly through room ideal for a thick scrog canopy.

Edited December 7, 2006 by thc24

[Taipan]

With an AC in the room you don't need, or want, a lot of ventilation. The AC will keep the room cool and reduce the humidity, and it will do it a lot easier if you don't exchange the air too much. The only reason you need to ventilate is to avoid CO2 depletion which doesn't happen as rapidly as you might think. I see your options as having your ventilation as a slow trickle running all the time, or if you go with larger fans, just run them once an hour for a short period. The rest of the time the AC will keep conditions perfect.

[Gazza2001au]

if u have a airconditioner in the grow room just block off those pipes add CO2 there u have a closed off grow room no need for vents and exhaust fans and u dont need to use a carbon filter for the inlet mould will only grow if the room humidity is over 45-50% and when the buds get really tight 6th week onwards pray them apart slightly to get some air movement in there

[Roadblock]

Thanks for the imput guys ,,, the mold spores Im paranoid about are Pythium and Fusarium types not green mold ,, as this is a clone room and first stage 2wks grow there is no buds or hardcore lighting ( demand) ... I had a torrid battle with pyth every summer for years ,, Ive systematicly eliminated every step ,, and it still comes back ,,,, my thoughts are its been venltilation all along with this room or lack off ,,, everything is great untill it warms up which then overwhelms my air next thing that sits the plants down a little and boom in comes the big P , which just loves our humidity in northern Aus .

 

I wouldnt like to close it off as its underground and sweats , big job to seal it up air tight to stop swaetng through walls , I think my best bet is pull as much air as possible through it ,, I think I,ll go 2 x 200ml centrificals , one in one out ,, there is a bit of backdraft so using centrificals on both ends should have the out fan drawing a little more than the in which will work that bit harder pulling in ,, should balance out I hope to cause a postive flow .

 

Rod

[Taipan]

One thing to keep in mind. If it's humid outside then high ventilation doesn't help, it just moves the humidity around. If the air is dry outside then the ventilation will lower humidity quite well.

 

A good AC should reduce the humidity of a fixed volume of air quite rapidly. You should see water continually pouring from it's overflow drain. If it isn't then maybe the AC is not working properly. For the AC to work well, if it is a normal wall or window mount type, you need to close the vents and run it on recycle for it to lower the humidity well. The moist walls wouldn't help and would obviously make the AC work a bit harder.

 

As a last resort in controlling the fungi problems, never tried one myself, but I have heard good results from "Sulphur Burners". Sulphur is an excellent fungicide, but is usually sprayed on plants and is not so good as it leaves a residue, but the burners just emit a small amount of sulphur gas into the air, kills all of the mould spores without damaging the plants or leaving residue. As it's a veg only area it would definitley not hurt. A mate of mine used to have major bud mould problems but since installing a sulphur burner the problem has gone. He can even continue spray routines a lot longer than he used to.

[Roadblock]

Thanks Taipan , I,ll look into that tip about sulphur sounds good !

 

When I say the room sweats , it does but not a lot and only when its big rain ,, the room works good when the aircon is running and through winter , this time I added another light which put the demand and heat that little higher and next thing I got Pythium in there , its all pointing to the airflow being down that llittle bit low , being in Rockwool the pots hold too much water in the first stages and this compounds the problem ,, if you slow thier metabolism by having restricted air the scene is set for Pythium or root type problems .

 

Ive fixed the too wet for youngsters Rockwool problem and found a way to get the best out of wool without its worst feature , too much water holding !

 

This may sound a bit wacky but it works fantastic ,,, when you transplant your rooted cubes into pots , just go to a 6 inch first and when you feed you can saturate it to give it a total fluid exchange , then instead of having a water logged pot have a funnel handy and a Vax vaccume cleaner , place the pot in the funnel and Vax out the water in seconds , this airates the pot bigtime and gets rid of excess water at the same time ,, the method really creates a good environment for developing root systems , Im making a little frame on the clone table that holds the funnel so I just drop the pot into it and turn on the Vax .

 

Rod