I have 2 gavita pro 1700e's in a 4x8 tent, you will need the controller. And that sometimes wont be enough. Even at 50% (which is the lowest it will go) still wasn't low enough for some young plants. I had to put a sheet of plastic between the light and plants for a week or so until they could take it. Other times the the young plants could take the light at 50%. I think the gavita is an awesome light but when i buy another led it will be an hlg, some of those you can dial back to 10%. And you don't have to buy a $250 controller.