I really wanted to get a Gorilla tent but cant afford one at the moment.
How many plant do you plan on growing? What style grow you doing? Soil, hydro, whats your setup like. Plan it out on paper to see how much room you will need to make sure you went big enough. Unless you just want the light to fill the room and you are just going to fit what you can in there,
5x5 is what 25 sq feet. I always go by the 2sq foot per plant rule.
sq foot divide by 2 for future grow space. Depending on how you are growing. scrog or what not doesn't matter as much but if you just straight up growing 2 sq feet is my rule anyways.
for example: 4 plants would require 8 square feet of grow space. Plus what ever else is in the room.
25/2 = 12.5 so 12 plants for the 5x5 tent. gives you plenty of room for veg and bloom. If you are only doing like 8 plants though that gives you room for what elver else is going to be in that room. fans, nutes, ect.
Everyone does it differently but I like the 2 sq foot rule. Worked well for me and always have enough room for the plants to bush out.
-Ammastor-
edit*** Oh and i know i lot of people will use 2 x 1000w for a 4 x8 so 4x4 or a 5x5 would be perfect.
a 5x5 will give you 40 watts of power per sq foot. Lumens don't seem to matter as much because the plants don't see what we are actually measuring. They see the wavelengths that we are measuring which are the greens.