600 Watt Cool Tube DWC SCROG Cabinet

This is my first "Official" indoor grow. Through much research and reading forums, this is the setup I've chosen to maximize the efficiency of the small area that I have to grow in. I have an area about 3' by 4' by 7' high inside a jacuzzi tub where I have a 15 Gallon Sterilite Deep Water Culture Bucket. I use Fox Farms complete line of products, along with Hygrozyme. There are two 4" air stones to aerate the solution. There are four plants in this bucket that are in rockwool cubes that were placed in hydroton that was placed in 5" net pots. There are two small fans to circulate air. Above, I have a 600 watt MH inside of a 6" cool tube which is about 12 inches away from the canopy. There is also a Tjernlund 6" inline exhaust pulling air in from the passive intake, through the carbon filter, through the cool tube and out underneath the house. There are a lot of twists and turns in the ducting that I worry is cutting down on my exhausting capabilities. I've been working out a lot of flaws/problems with my setup lately but will continue to post and possibly upload pictures.