1000 watt in 5x5 space soil

This is my second grow. I was pleased with the smoke from my first grow however I've been told my 1000 watt light should have produced at least a pound.

I'm using a 1000 HPS in a 5x5x8 grow tent. How can I increase my bud size?

Strains: Green Crack, LA Confidential and True O.G.

Thanks

need more info. temps ventilation how long did you veg for what was your actual yield pics are also worth 1000 words

Bro you want a pound of weed grow 16 plants...each to the 1 oz size.... thats easy for your third grow.... if you grow them to 2 oz ...thats 2 lbs

I grow under 4 -1000s and get about 6 oz per plant on the average.....it depends on strain, nutes and how you grow it