Not Enough LED Lights in a Large Indoor Grow Space Are The Makings for a Disaster aka Small Buds
A regular complaint about LED growing lights from some medical marijuana medicine growers is that they just don't get the harvest that they were hoping to get as compared to previous grows using HID growing lights.
Or things might look great when growing - nice sized leaves, lots of legal medical buds, but coming up short on dry weight because of lack of lighting, getting airy buds and not the fat, dense buds they been used to getting from their harvests.
If you got wispy looking buds like the little nug pictured here on the right, then your main issue most likely is that you are trying to grow way more than your lighting can handle. Trying to demand that 90W LED growing light to totally flower all your ladies in a 4'x4' grow area is not going to work.
First, you need to reduce the area of coverage - by about half - of what the manufacturer states the lights can handle for the average green thumb growing flowers or herbs for food. So now you can use that 90W LED grow light in a 2'x2' grow area (enough for a few good plants or perhaps even a SCROG/SOG grow) and come away with fat, dense buds like what you see in the photo on the right with the red background.
I have already let you know that there are lots of factors that can manipulate the coverage area of LED lights, here's a basic guide to what I believe are decent growing areas for a particular wattage of light. There are many makers of LEDs and many more different wattages of lights so here is a short list of commonly used sizes. All the lights that are listed are tri-band and 5 spectrum growing lights.
By keeping these guidelines in mind with your growing efforts, you should see your harvests match or blow away your usual expectations.
Guide for LED Grow Light Coverage
Space for Vegetative
Space for Flowering
4' x 4'
2' x 2'
5' x 5'
3' x 3'
6' x 6'
4' x 4'