Hi Chedz
On your light:
I grew for 2 yrs using 600w Mh for Veg and Hps for bloom.
I found, that I got better (best) results with a single "Eye Hortilux blue hps" for veg and bloom.
I would really try to get the temps down.
When my temps get 90deg F or more, my yield goes dowm, substantually.
I don't have an easy fix for you.
I have changed to using A 1000w now and increased my yield by 100+% in the same space. 4'x4'
good luck
On your light:
I grew for 2 yrs using 600w Mh for Veg and Hps for bloom.
I found, that I got better (best) results with a single "Eye Hortilux blue hps" for veg and bloom.
I would really try to get the temps down.
When my temps get 90deg F or more, my yield goes dowm, substantually.
I don't have an easy fix for you.
I have changed to using A 1000w now and increased my yield by 100+% in the same space. 4'x4'
good luck