First Setup help needed

Hey all. I have been reading through this site for years but never created an account until now. I am now living in a place where i can legally grow. I am going to be purchasing a 4x4x6.5 grow tent to be doing both Veg and Flowering in.
I want to not go cheap at all on this but not overspend also.
Here is what i was planning on buying for the actual set up

4x4 secret jarden tent
6 inch air cooled hood
600 watt hps and mh bulbs
600 watt digital ballast
6 inch carbon scrubber
6 inch inline fan- still unsure what cfm to get but i am thinking at least 400 because i am running all the way to the back of the attic
6 inch ducting


Does this seem like a solid setup to you guys? Any helpful advice before i get started?
Also, will it be necessary to have another inline fan as an intake or should i just leave the flap open and rely on the one 400 cfm fan to create the right pressure and suck air from outside of the tent? (i am still unsure of how to keep light out if i leave the intake open)
I am planning on having the scrubber hang in the grow room run to an inline fan then to the light and out the tent with duct

Carbon filter-inline fan-flow hood-duct going to attic

Thanks a lot for any info that can be passed along and looking forward to posting my progress

Anyone out there?

A 400cfm fan is huge. How much 6" r u running? Also what is the filter rated for re cfm? Thats about as much as i can help you with im an HVAC guy lol. R u running flex or rigid pipe? I can tell you exactly how big of fan is needed with out dealing with a huge noise issue. I would go with passive intake but if you are using a 400cfm fan there will be quite a vortex at the intake lol. Even if you get 300cfm thats a total air change every 20 seconds. Thats way more than required IMO. Also depending on heat you may need to bring in cool air. I have a 600 and 8 t5's and i have to bring in cool outside air to deal with temps, room is 8x8x8.

400 CFM is kind of overkill but better too large than too small. Make sure you get a speed controller.

I run this fan http://www.amazon.com/Hydrofarm-Active-Air-inch-In-Line/dp/B002JQ14F8/ref=pd_sim_hi_1

with this controller http://www.amazon.com/SE-Step-Speed-Controller-Electronic/dp/B000HQAVNI/ref=pd_sim_hg_3

and never run it above 40% to cool a 600W HID in a 5X5' room

Those cheap tin in-lines are junk.

Thanks a lot for the advice guys. Deals online are way better than any of the stores around town. I think ill go with that fan that you suggested AimAim and run it on a lower setting with the controller Keep in mind that i have not bought anything yet, i want to do more research before i invest my money. I was planning on running flex pipe.

How much noise does that hydrofarm produce? Tent will be in the bedroom so i want something fairly quiet. Since i dont need 400cfm would getting a fan with less be mroe quiet?

AimAim said:

400 CFM is kind of overkill but better too large than too small. Make sure you get a speed controller.

I run this fan http://www.amazon.com/Hydrofarm-Active-Air-inch-In-Line/dp/B002JQ14F8/ref=pd_sim_hi_1

with this controller http://www.amazon.com/SE-Step-Speed-Controller-Electronic/dp/B000HQAVNI/ref=pd_sim_hg_3

and never run it above 40% to cool a 600W HID in a 5X5' room

Those cheap tin in-lines are junk.

Click to expand...

Why the 40%? Is it noise? Just curious. If you exceed the rated cfm on filter you will have odours so just keep that in mind as well. If you know the static of the complete system no need for a controller IMO. just buy accordingly re CFM and air change requirements. My situation is probably different as odours are not a huge deal but temps are so my ventilation is controlled by temp, if shed gets to cold all ventilation is turned off, boy does it get stinky lol. I use 200cfm whole house hepa filter and have no issues with smell when on.

I run pretty much the exact set up you were asking about, I have a 4x4x7 tent, a cooled 600, and a 6" fan/ filter combo, in my room, ducted to the attic. Dont put the fan in your tent, have the filter ducted to your hood, ducted out of the tent to the fan and then to the attic. Suspend your fan with bungee cords as close to your attic acces as possible and it will be much quieter and move plenty of air. My fan is 440 cfm and it may be overkill but my tent only runs 5 degrees warmer than room temp. Get a good ac filter, remove the cardboard frame, cut it about 2" bigger than your flap on the bottom and stick it on, the suction will keep it their, it will keep air the incoming air clean, and its also a light block. I would definitely recommend using that 6" fan, can never have too much air goin thru a tent, if you dont have solid negative pressure your house will stink if you grow funky strains

When i walk outside in the mountain community i live in the air smells of freshly growing herb. My neighbor has a plant just flowering in his window, so smell is not a HUGE issue. I guess i am confused about the filter and fan combo.....so if i get a fan rated for 400cfm then i need a filter rated for 400 cfm also? What if i had a fan at 400 cfm and the filter rated for 300 cfm? I assume its more important to make sure the fan is a higher cfm than the filter. Correct me if i am wrong here.
Thanks a lot for the help

waterdawg said:

Why the 40%? Is it noise? Just curious. If you exceed the rated cfm on filter you will have odours so just keep that in mind as well. If you know the static of the complete system no need for a controller IMO. just buy accordingly re CFM and air change requirements. My situation is probably different as odours are not a huge deal but temps are so my ventilation is controlled by temp, if shed gets to cold all ventilation is turned off, boy does it get stinky lol. I use 200cfm whole house hepa filter and have no issues with smell when on.

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Its crazy how many different views that people have on the placement of the fan/filter/duct. Some say to put the fan before the lamp, others say after.

Jbone77 said:

I run pretty much the exact set up you were asking about, I have a 4x4x7 tent, a cooled 600, and a 6" fan/ filter combo, in my room, ducted to the attic. Dont put the fan in your tent, have the filter ducted to your hood, ducted out of the tent to the fan and then to the attic. Suspend your fan with bungee cords as close to your attic acces as possible and it will be much quieter and move plenty of air. My fan is 440 cfm and it may be overkill but my tent only runs 5 degrees warmer than room temp. Get a good ac filter, remove the cardboard frame, cut it about 2" bigger than your flap on the bottom and stick it on, the suction will keep it their, it will keep air the incoming air clean, and its also a light block. I would definitely recommend using that 6" fan, can never have too much air goin thru a tent, if you dont have solid negative pressure your house will stink if you grow funky strains

Click to expand...

COflower said:

How much noise does that hydrofarm produce? Tent will be in the bedroom so i want something fairly quiet. Since i dont need 400cfm would getting a fan with less be mroe quiet?

Click to expand...

At 50% or less power it is whisper quiet, and around 30-40% is what I run it at in a 5X5X8' room with a 600W HID cool tube. Any higher and it sucks out too much heat (I need some additional heat in my basement room and basically control my temp by adjusting fan speed)

So yes I think its very quiet.

waterdawg said:

Why the 40%? Is it noise? Just curious. If you exceed the rated cfm on filter you will have odours so just keep that in mind as well.

Click to expand...

Dawg, as I explained above I NEED the heat over cool months in my basement. Around 40% makes my room a perfect 75-80F. And 40 gives me plenty of fresh air exchange which is all passive, provided by the inline fan. Also I do not run a filter.

Yeah, when you rely on the lamp for heat im with you on the speed controller, use it like a thermostat. I dont have a winter where I am so keeping the tent cool when its in the 80s outside in january requires some good air flow. Wish I had to worry about it being too cool. Odor may not be a legal concern but having your house stink like shit all the time would get old. Inline fans pull conciderably more air than they push so the closer to the end you get it the better. Insulated duct and suspending the fan with a bungee cord makes them quiet, I can hear my oscilating fans over my 440 cfm inline fan. The bungee eliminates rattles and the insulated duct absorbs the ambient noise.

And if your fan is too big for your filter it will just pull the air thru too quick and it wont have time to eliminate the odor, if your filters too big for your fan the fan will work too hard to pull thru it and you wont have the negative pressure u want.

Hey Jbone i am curious, how many plants are you fitting in the room and how tall do you let them get before you flower for two months? Also if i were to get 6 plants in there under the 600 watt with ideal conditions and nutes, what could i expect off of each plant? I am shooting for 4 oz each plant. I see some people cramming 12 plants in there and dont think that allows much light to get to lower buds.

Jbone77 said:

I run pretty much the exact set up you were asking about, I have a 4x4x7 tent, a cooled 600, and a 6" fan/ filter combo, in my room, ducted to the attic. Dont put the fan in your tent, have the filter ducted to your hood, ducted out of the tent to the fan and then to the attic. Suspend your fan with bungee cords as close to your attic acces as possible and it will be much quieter and move plenty of air. My fan is 440 cfm and it may be overkill but my tent only runs 5 degrees warmer than room temp. Get a good ac filter, remove the cardboard frame, cut it about 2" bigger than your flap on the bottom and stick it on, the suction will keep it their, it will keep air the incoming air clean, and its also a light block. I would definitely recommend using that 6" fan, can never have too much air goin thru a tent, if you dont have solid negative pressure your house will stink if you grow funky strains

Click to expand...

You would have to be careful venting into an attic in cold climates as it will create tons of moisture. Warm climates not a concern. As far as the odour as long as you create a negative pressure in the tent and dont overpower the filter odours should not be an issue. All fixtures and filter should be upstream of fan imo so your not blowing odours out the cracks in the pipes before the filter. I grow in a shed so when temps fall and ventilation shuts off it does smell

Im going to look into a control that changes speed dependant on temp rise or fall. Any thoughts, controls? I was going to build a modulating damper for intake based on temp but motor control would be easier lol.

COflower said:

Hey Jbone i am curious, how many plants are you fitting in the room and how tall do you let them get before you flower for two months? Also if i were to get 6 plants in there under the 600 watt with ideal conditions and nutes, what could i expect off of each plant? I am shooting for 4 oz each plant. I see some people cramming 12 plants in there and dont think that allows much light to get to lower buds.

Click to expand...

Like everyone will tell you, yield and when to flip is strain dependant, I run 4 plants at a time, some get flipped at 16" and some at 20", I try to finish at about 48", and shoot for a pound. 4 big plants is plenty in a 4x4, 6 would just be a pain in the ass for me, I know people run more plants than me and yield more than me but 4 is all I need