Sharp Eye you have.
I have a question about your filter system. It looks like you are blowing the air through it as opposed to sucking air through it. How is that working for you? I have only used the filters in the tent and the exhaust hose open. Using one instead of 2 would save me money.
You are correct I do have the filter and blower outside the tent, all though that wasn't that hard to guess. From my experience it works very well.
Here are a couple of closeups
View media item 1690804View media item 1690803 As you can see the Filter sits directly on the floor with the blower on top then the dryer hose up to the T fitting. From the T fitting there are to extensions to the adjustable 90 degree elbows with another extension to penetrate the tent a bit better. Very cheap set up actually. I think I'm into the entire system for under $100.
I originally went that way because my first tent was only 5'7" tall and I was concerned that if I had the blower and filter in the tent it would take up room in the top of the tent. I have also been one to seek simplistic solutions when possible. By putting the filter with the blower outside the tent it's saving space inside and I don't have to use anything to strap or hang it anywhere. Being between the two tents saves space and is out of the way. Additionally I have light control timers on the wall in the same space. All nice an tidy.
Originally with only the one tent I had already a shelf outside at the level of one of the pass thru holes. So it made sense. I used a 4" Metal duct work 90 degree adjustable elbow and a couple of extensions and put it all together. Worked so well that I needed to by the bars to keep the tent from sucking in from GGT.
Speaking of Gorilla Grow Tent, a customer service rep turned me on to the idea of using one blower for more than one tent. He told me in passing (sort of a Oh by the way) that many growers using their tents connect multiple tents together with ducting and run only one blower and filter. Apparently according to him some people are daisy chaining several tents together kind of like in series, while others are doing a parallel idea where all of the ducts go to a manifold into the blower.
I had already determined that the CFM of my adjustable 4" blower was rated at 180CFM. My 2x2.5x6'7 GGT works out to be 32.5 cubic feet. That would explain the major sucking in factor at higher blower speeds. My new tent is a 2x4x6'7, so it is 52 cubic feet. Total of both tents equals 84.5 cubic feet. Approximately half of the blower capacity at full speed. NIce!!!
One of the things I continue to see in the micro/hobby/home growing world is distributors/Hydro stores up sell people to equipment that exceeds peoples basic needs by a lot. I get why on several reasons. Stocking multiple sizes is more expensive, and selling the larger 6", 8" and larger Blowers and Filters along with larger duct work is more profitable. It's also easy to tell the unsuspecting novice grower he needs lots of air movement and the bigger sizes will certainly do that. But it's not necessary.
I apply quite a bit of mechanical engineering to many of life's applications. So the idea of calculating the CFM needs of air movement was a natural. I do the same thing with lighting in the tents. I have an entirely different story on how I calculate the lighting needs and also save on electricity and reduce the need for cooling the inside of the tents.
Long story to a short question. However I like to give reasons to why I do things because they make sense and many people haven't given them any thought. Additionally many people follow form of what others are doing and don't consider there are other options. I like options.