Hey Dragontec, welcome to the forum.
Looks like you saw my build for a flowering rig. It's a great option for the money, and I don't think you'll find any better options for less. Also, my turnaround time on the backorder of those strips was 3 weeks from date of order. Hopefully you get yours sooner.
Using the 2x hlg-320h-42a drivers at max, it's probably too much for a 4x4, but it might stretch to a 5x5 like you said, if you have very reflective walls. I've had good results under less efficient LED lights run at 25w/sqft, but it's kinda pheno dependent.
You might be able to get away with just that build in a 5x5. I guess you can try it and see how it turns out. If you find it's lacking, you'll probably want some side lighting or a few extra strips outside of the area covered by the main light.
I'd say an extra 10 strips attached to an extra 320h-42a would solve the issue. Place the main light in one corner of the 5x5 space, then add 5 more strips on each edge not served by the main light. That would knock it out of the park for sure, and you'd probably have to dim all the drivers to 75% or so to avoid stressing the plants.
Are you cash cropping or just growing for personal in that 5x5 space? That would be my first consideration when thinking about using more strips. What's the goal?
Please let us know how it goes!
