OgKush Small Buds

Hellow All, I am currently in flower with some Ogkush, Obsidian Ice, and Critical Kush.
I am trying to figure out why my Ogkush has such tiny buds. It is my first time growing any of these strains. My setup is as follows. 12x7 area, 1000 watt balast split running 2 600 watt hps bulbs and 1 600watt metal halide,CO2 at 1500ppm. The area is controlled by a atmosphere controller and a Co2 controller.Feeding: Roots Organic according to directions on bottle. Added blood meal, jamacain and mexican guano, kelp with calcium , fox farms bloom.
This is the fourth week of flower not counting the first 2 weeks. The plants are filled with buds and the aroma is very pleasant. However, the buds are not growing to any reasonable size. I am hoping it is not genetics. So, let's not take that into consideration, please. So what else can be done?

Hello,

what kind of medium are you using? soil? coco? DWC?

I've never heard of someone splitting a ballast ? How do you do that (don't hps lights need a starting cap) and why ? Call me crazy but if you had 1800 watts of lights running on a 1000 watt ballast would you not have only have a 1000 watts maybe it could push 5.. 10 .. even 20% more but no way could it do 80% plus startup current you'd think the f'ing thing would melt down in a fiery way. Maybe you don't have enough light even at 1800 watts over 84 square feet you'd only have 21 watts a square foot and about 11.9 @ 1000w. That seems low to me, 1200w in a 4x8 works well. Maybe get a cheap light meter and see what's up in the garden. Sounds like a pro setup though I hope you figure it out. Peace