Preventing Unnecessary Stretch

In the past I have always kept the lights as low as possible to prevent too much stretch. However, now that I'm rocking this 315w cmh in a 4'x4'x6' cabinet with okay ventilation.. I can't drop the light too low without heat stress. In this picture the larger plant is sitting about 27-30 inches away from the light. I can bring the light up as far the red hooks at the top. Apparently my last run at this the ladies all grew into bushes and the buds took a lot of heat damage. I have my temp gauge sitting on top of one of the buckets usually, and the temps are usually 70-80F with a RH of 40%. I'm about to flip to flower (at least for the larger plant).. just hoping it doesn't shoot up 3 feet. -_-



Suggestions? Thoughts?

Air cooled reflector?

Hi I am new also have u looked at lst you can watch videos on u tube about it don't know if too late to do or look up on here how it is done don't know if u have much room to do it though sorry not much help just a thought

These generate some heat at canopy level, add a fan to blow across the top of the canopy. I see one on the floor blowing at the plants but you should have another blowing across the bottom of the hood where the heat is highest. They don't generate enough heat to bother with a cool hood type setup imo.

Having the light that high above the canopy is not going to help reduce stretch either, try 22-24" which is good for that tech.

Main way to "control" your stretch is to allow for it, meaning don't wait too long to flip and know your strains as some stretch more than others.

Another way to manage canopy height is spread them out. I use these sometimes for larger plants for keeping the canopy even and support later on. I buy them at the dollar store. They'll slide down the inside edge of any pot, I use 2x per pot, one on each side and weave the colas through them as they stretch.