New personal best grow

hello just produced new personal best, can i increase yield anymore? here are the stats

3 plants unknown strain but proven producer
run to waste
coco coir
30 lt pots
1.2 meter x 1.2 meter grow tent
200mm exhaust fan
150mm intake fan
600 watt hps
whole range of house and garden nutrient and followed their feed chart to e.c and ph levels(i did swap week 4 of flowering for no nutrient just used there straight top boost at a higher rate)
4 weeks grow at 18/6 and 9 weeks flower at 12/12

Total of just over 27 dry ounces

it is my 5 or 6 grow but i have just started on the 600 hps and the H&G nutrient for that grow

could i get any more from them or would i have to increase the light to a 1000 watt or 2x600watt

any advice would be nice, i am new to this site. cheers

Sounds epic - - why not give 2x600w a try; Could throw in a metal halide... or led supplements.

good job man! would love to see pictures!

Yeh cheers mate, I have 2 rooms now. the other slightly larger(18 sq ft). i am currently doing a little experiment. I have put 2x400 watt hps and 2x130watt fluoro(14000k) in there, same size fan but with a y-joint to exhaust from 2 points in the room. Same unknown strain in there, just started 1st week of flower. In the tent with 600 hps are 3 white rhinos in 2nd week of flower. I have read that blending the two light spectrums is a good thing. I will see how they go. I dont think the whites rhino will produce as much as the unknown strains 27 dry ounce personal best.

Will take a few pics of current grow and post soon