I have a version of this. Improvement would include exhaust STRAIGHT VERTICAL, T6 inside tent
Intake works best at bottom of tents, allows natural air dynamics enhanced movement. Also hottest tent needs coolest air first. Flower tent is 1000watts actual and 300 watts in veg tent (metered, Thanks Amazon)
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My feeling is that you’d probably be moving a lot more air if you relocated the “bridge” fan & installed it next to your existing exhaust fan with its own exhaust tubing & carbon filter, & then you probably would also need to increase the ‘intake area’ between the two tents by a lot by adding more hoses or bigger hoses, as well as increasing your existing intake area at the window by a lot as well, maybe by double or more. Those fans in series are just fighting with each other, for maybe some minimal gains. Put them in parallel with enough intake area & they will want to eat.
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Absolutely when I get off restriction, changes get made.
Work in progress and waiting for version 10.
Thanks.
I am stoked for winter.
It will take 2 years to re-shape my yard and 6 months for the other grow needed improvements.
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If you do it, you might be looking at needing to provide around 200 to 225 square inches of cross-sectional surface area at the ‘bridge’ intake between the two tents, & also again at the at the window. You’re only at about 40 sq in at the window, & 28 sq in at the bridge, & those don’t get added together. So your final exhaust fan is basically being given 28 sq in of intake area (before you put the ‘bridge’ fan in the way =) ). That 225 sq inches is just a guess based on my fan needing just over 4x its own intake area before it got to zero static pressure, but to check yourself you can fully install the fans in parallel with their own ducts & filters, then seal up all intakes on that tent, turn the fans on to max, then slowly open the main door until you lose all negative pressure. The fans are now pulling as much air as they are going to, given an efficient install of their own tubes & filters etc. Measure the area of the open portion of the door & you know around how much surface area you need to provide across the openings of the ‘bridge’ & also again at the window intakes. I’d probably add a little more on top of whatever you get, at least to the ‘bridge’ ports. You want the bridge to not be restrictive. Plus don’t forget you will give up CFM wherever you add additional tubing. You could put the bridge area in there as multiple tubes so you can put the air where you want it, or you could do one big port, or whatever. But more smaller tubes would be more restrictive than less tubes that are larger, for the same given surface area. At your window intake you could stay a little under the ‘bridge’ surface area, & you’d probably end up with a little negative pressure & still minimal restriction, which you want. If you do it & end up needing a little more negative pressure, tune it at the intake at the window by slowly reducing/ covering intake area until you get where you want to be.
Thank you. Yes I flunked the math originally Smoked and thought 2x4 beat 1x6.
Abucuss does not work like before.
The journey continues. I have never harvested AND cured for 3-6 months. Now is the time, although, I am cheating and mixing current harvest with commercial and swapping back for taste and smoke comparisons. Smile meter works good, but thats Jack and 5 oclock somewhere.
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Truthfully, I’m not sure I would want to run the tents hooked together.
Are you adverse to running them separately?
You’d have to repurpose the 'bridge" fan as an exhaust fan for your veg tent, & also provide separate intake air to both tents from the window. One 6" exhaust fan might need a minimum 120 -150 square inches of intake surface area for one tent before it loses negative pressure. Just a guess, but you can do the ‘door test’ to more accurately see what it needs. Add in tubing & bends, & it might need a little more. Straight runs of tubing (properly-sized) aren’t as bad as bends. Put a couple bends in it & CFM generally starts to disappear rapidly. You might want something like 14" ducting for each intake run.
Thanks @SilvaBack203 , I think my ph might be a bit low but, they’re not dead… 
Thanks for all the diagrams and charts too guys. Like I said, just too much to handle in the amount of time I have.
The light, for 1, puts out a ton of ir. Great for leaf temperature, if you’ve ever considered it before 
Then there’s my circulation setup. No need for the exhaust yet, temps are fine and I’m not drawing in any outside air,…yet. Those 2 things alone have taken a lot of time. I’m trying to dial too much at once.
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@Beefy are you sure that your leaf temps are hotter in comparison to the air temp directly above them? Or did I mis-read what your results were? Is your air temp sensor close to where you are taking your leaf temp readings from? Leaf temps hotter than the air temps right around those leaves seems a little odd, if that is the actual condition.
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@PhotoFinisH I’m still working on figuring this all out. Sorry, but I never knew ANYTHING about lst, and humidity…, thought i was done with it after seedling stage. I have 2 temp sensors. Both in the tent. Is that close enough? Lol. Seriously it’s more keeping it shaded from light that doesn’t affect air temps. I’m pretty sure I have a good reading. If and when I’m ready, the only problem I see in getting lst above ambient with this light, is maintaining humidity throughout the day. Especially in the heat of the day, a/c cycles often and buh bye humidity. Don’t have humidity controller. Didn’t know lol. Short list.
Like I said, new to the forum…check. Not knew to growing…, I feel like I am. Leds, far red spectrum, lst and humidity control is all new to me. I got lucky because i grew in a basement I believe. Naturally cool and humid. Now I know, but playing catchup. Its all going to work out, just not pushing things until I’m ready. My adjustments are based on trying to stay around 1.0 vpd with a lst of +1. Canopy is ~20-21" below light, which is at ~65-70%. Recommended is 18-24" at 75%. Lst is as much as +3 at lower height with this light at that intensity. 
Yeah I’m just learning about this too. Can you check your leaf surface temps & the air temps & RH again? Find the hottest leaves at the tops with your IR temp gun, & put the air temp & humidity sensor even with/ next to those leaves, & see what they say. It would be a bit odd to have leaf temps even with or hotter than the air temp right around them. Generally the leaves are able to keep themselves a bit cooler than the surrounding air temps. I don’t think that you want to try & get the leaf temps even with or higher than the surrounding air temps. They will try to stay cooler than rising temps until they go into “self-protection” mode & stop transpiring. Then they would probably start to heat up towards & maybe even past surrounding air temps (bad).
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Positioned at top of canopy (top leaf height). just a couple of inches difference is big for the sensors.
@PhotoFinisH I understand what you’re saying, trust me, I experienced +2 and brief flashes of +3 degrees in between air from oscillating fan hitting the area. I could not keep humidity high enough. This light is for professionals it seems. That’s why it’s at reduced intensity and a little higher.
Thought you said air temp was 3 dimensional in your tent? It should be if you have good air movement. It’s not like these plants are 3 feet tall. I’m relying on the faster responding sensor on the inkbird unit. It’s shaded from the light and at the same level or actually a tad higher than canopy.
@PhotoFinisH Wasn’t it you that said I might find I need to run a higher air temp to achieve similar results. 
That’s to try and reach the same leaf temp right? I don’t have previous experience with leaf temperature, but I can tell you it’s not a problem reaching what I described with this light. With the distance I have it at I am seeing at or slightly above air temps. My humidity is in upper 60’s. In flower I’m worried they will get too close to this bad boy.
I agree about not wanting higher than air temps…right now. I’m not dialed in. I will say this, I can grow at much lower temps with this grow light. Why? Because leaf temps. I watched a review of this 1 before bying and it hits all the marks. Samsung lm301b diodes, far red, quality build at a decent price. The only negative is the Done drivers. Reviewer had not heard of them. I know from looking that meanwell are good, but this is supposed to be a budget light.
He put it to the test and when he did the spectrum analysis, he mentioned the huge bump at 740 or 750 blah blah blah lol. It meant nothing to me at the time.
@DEEPDIVERDAVE I like CFM. Rate of flow metrics are good. I want as much CFM as my fan will give me.
A good Airflow efficiency equation that I like is CFM divided by Watts.
Yes, the line of thinking is that if you replace your HIDs with a comparable LED light, then you will probably see a lower leaf temperature with LEDs vs HIDs, at the same given air temperature .
So if you had your HID grow ‘dialed’, & you switch to a comparable LED & try to run the same air temp as the ‘dialed’ HID setup, then your plants leaves might be cooler & can grow more slowly, & if so, you would want to try to gain back some leaf temps to get them to where they were with the HID setup. Raising the air temp can do this. That was all that I was saying. But you could start out by running lower air & leaf temps if you want, it’s just that the plant might grow more slowly. Later on you can try to push the limits. No one can really tell you what the best numbers are either, it’s going to be plant specific. But I think a leaf temperature range of maybe 70f (slower growth) to 80f (faster growth) is probably a safe place to be in for most plants. Right now I’m happy with a max leaf temp of 82f in my main cab, & a max leaf temp of 72f in my seedling/ veg cab.
But the leaves are usually cooling themselves off, & they should end up cooler than the air around them generally. At least that is what I have observed. Maybe right when my exhaust fan turns on & draws cold air into the cab I might see warmer leaves than the air for a few moments, but the leaves will cool down quickly & lose (for example) 5f to 10f from the cool air, & they’ll end up cooler than the cool air eventually, due to the leaves transpiring.
In my mind, if the leaf is the same temp as or hotter than the surrounding air temp, then the leaf might not be transpiring well or at all, which in my mind would not be good.
Not sure what to make of your venting system or if that could be causing issues somehow.
What do the plants look like now?