pulling air through my lights messing up light distribution

i have a setup with four 8" 600w lights in an L shape and they are air cooled. when i turn on my 675 cfm fan my ducting sucks together and twists my lights causing uneven light distribution. anyone have any advice on how to get my lights to stay in place without having to add another fan or redesign the grow area?

Just tape (guess with what? hehe) the ducting together so that there is no loose ducting and adjust the lights for that... this method would solve your problem...but the downside is if you have to move the lights up or down you'll have to readjust...

You might need a bigger intake for less restriction. I use insulated flex duct ( homedepot sells it) it's a little more rigid than the cheap stuff and keeps heat out better.

good luck

I had the twist problem to. All I did was get real clamps and put them on. With fan running tighten them down with lights aimed where you want. Fixed. Also when you raise you lights if it twist all you do is loosen them and move it around. Better then tape.

The deformation of the ventilation is due to a vacuum in the ducting caused by flow restrictions. Depending on your setup, place the fan at the intake so it pushes air and problem solved.

The question is Do you have any sharp 90 degree angles? Ducting Kinked a little to make it fit? The ducting flow needs to be smooth and no sharp 90 degree angles, 90 degree angles really mess up air flow....