For the record, I have tried registering on these forums for like a year and for some reason, my account never gets activated to the point where I can ever post. Anyways, this is my setup. Tent: 2 x 4 x 5.5 Exhaust: 170 cfm HTG brand inline through 4in ducting Intake: 12in desk fan blowing through intake slat Circulation: 10in desk fan pointed at plants Light: 400watt Sunmaster Warm Deuxe Hood: HTG 6in Eurocool vented hood As is, I'm getting temperatures averaging 74*-81* during the day which I don't have a problem with but my hydro reservoir in the tent has been climbing to the mid 70's during the mid day. I would like to drop the average temp 5*-8* so I won't have to worry so much about my water temps. I could use some suggestions so here is a little more info on my limitations. 1) I'm not on a super tight budget but running out and spending a few hundred dollars isn't all that possible for me right now. I would prefer not to dish out a bunch on this one. 2) My apartment doesn't have AC so the ambient temps in the room get a little warm. The grow room is also my bedroom and I am comfortable with the current temperature. I would rather increase the efficiency of my ventilation system than sacrifice a comfortable bedroom temperature. 3) I'm probably not going to be using a carbon filter. The stress on the fan isn't worth it when battling temps so I'll probably be using ONA gel for odor control. 4) I can't upgrade to a 6in fan. The holes in the tent are 4in and I'm not willing to cut the fabric. 5) I can't take my reservoirs out of the tent. I'm doing a 2 tub 14 gallon DWC. I'm brainstorming a low to the ground aeroponics system with a remote reservoir but that won't see daylight until next harvest. I've played with a few ideas already. The cheaper ideas would be ideal, but I don't know if they would work or not. A cheap fix that doesn't work is a waste. A) Fit 6in computer fans to the hood, use the inline fan to just vent the tent. Would cost about $30 but I don't know if it would work. B) Install a 4in duct booster fan at the end of my duct work. $15-20 for a cheap booster fan. I was under the impression that these are more for assisting air through long straight sections of pipe, not assisting with suction in a small area. http://www.htgsupply.com/Product-4in...e-Duct-Fan.asp C) Buy a portable air conditioner for the room. I can't buy a window unit because I have sideways sliding windows. The cheap AC units that use water circulation are out of the question. They are a pain. The cheapest decent portable AC runs $300+. This is my last resort.