Kris, airy buds are sometimes a result of daytime / nighttime temperature differentials
Could probably caused by a wide variation between your daytime and nighttime temperature. If using lights indoor you can do a number of things to keep temperature under control. The simplest adjustment is to make sure your lights run at night when it is coolest and are off during the day
You have MORE than enough light with what you are using…
WW is a hybrid and part of her heritage is sativa. Sativa can usually have less dense buds than Indica so it could be a genetic thing. Also, you could have harvested too early…WW loves her 2/3 days of darkness before harvest during which she thickens up her buds…
Either way, I have had airy buds and as long as the high is good, who cares. Important - airy means they can dry quicker so make sure you have your curing jars with bovida 62% packs while curing.
UVA/UVB - these lights are either incorporated into your growing lights or you add them on. They should only be on 2 hrs a day…during mid to late flower time. They help increase terpine and thc production. That does not necessarily mean thicker buds, just better tasting and more effective
I use simple 25w reptile UVA/UVB. If you are satisfied with the effects of your weed, not necessary