These lights are bright and dont make much heat. I...

So you have 16 x 20w bulbs so 320w of total power. 45w of led is recommended for 1 square foot so for 9 square feet you need 9 × 45 = 405w so you are not so far and I'v seen nice harvest with less than that. However to maximise you led light distribution I recommend you to take a look at @Athos diaries as he his also using led bulb with a method he call screw in led : you just need to remove the opaque part of the bulb ( I think it is the bulb it self) to only keep the light but check his diaries it's better explained than I can do 😊