Hello friends,

This post is kindof long... Cheers to those who actually read it all .

With information from this site, I was able to successfully complete a rubbermaid tub grow. So I have to THANK YOU ALL for this wealth of information.

Now I am planning to build a second, slightly more classy cabinet. As a patient I have an easy supply of clones, so my plan is to start the clones in the rubbermaid, then move them in to the new cabinet for flowering when they are ready (somewhat perpetual style). I may eventually end up with a mother plant in the rubbermaid, but for now I'd like to explore different strains.

The new cabinet will have dimensions 28" x 34" x 65" tall, and will be powered by a 250 watt HPS. This gives about 35 cubic feet of volume. I'm pretty handy, so there will be a lot of DIY going on. I will be building a bake-a-round style cool tube, and a DIY carbon scrubber (bed thickness of 1", length/diameter dependent of some other variables I'm still working on). The DIY carbon filter and inline fan will be suspended from the top of the cab with bungee (or old bike tube). This will take up about the top 10" of the cab. Not a problem, I will be using the SCROG technique. The cool tube will be just below the scrubber and fan. Air will be drawn through the carbon scrubber, through the DIY cool tube, through the inline duct fan, and out the top of the cabinet.

That brings me to my question... Should I go with a 4" or a 6" duct fan? I am not going to skimp on this. My top choices are the Elicent 4" or 6" or possibly the Soler & Palau (but I have heard about issues using a speed control with these). The bake-a-round is about 4" diameter, so I was hoping I'd be able to get away with the 4" Elicent (about 150 CFM) with a speed control. With that fan, I could lose about 30% of my airflow to the static pressure of the scrubber, cool tube and ducting, and STILL extract about 3 room volumes per minute. I have NO idea how close that 30% is to reality, that's the problem...

The other option would be to go with a 6" fan, but with the extra diameter of the ducting, extra size of the fan, and extra length on both ends of the cool tube for 6" x 4" reducers, it would start to get a little cramped in the upper section of the cab. I don't have enough experience to make this call, but it just seems like a 6" fan would be overkill for this little cabinet. And it would cost a little more, but that's the last consideration.

So what do you think, guys? What would you do?
SpicySativa Reviewed by SpicySativa on . Little help with my 250 HPS cabinet design? Hello friends, This post is kindof long... Cheers to those who actually read it all :). With information from this site, I was able to successfully complete a rubbermaid tub grow. So I have to THANK YOU ALL for this wealth of information. Now I am planning to build a second, slightly more classy cabinet. As a patient I have an easy supply of clones, so my plan is to start the clones in the rubbermaid, then move them in to the new cabinet for flowering when they are ready (somewhat Rating: 5