What to increase?

I have heard two different sides of this. Some people say to stay at the same pressure but increase the time in the tube. However, I have also heard that anything past a total of 30 mins in the tube is useless and can even be counterproductive. I was wondering if I should stay at a 30 min total time within the tube and slowly increase pressure (.5-1 hg every 2 weeks) or increase the time?

My routine :

10min jelq
10min pump
10min jelq
20min pump
10 min jelq

I will eventually increase the jelq times but right now, my concern is about the pumping.

Short sets (6 - 10 minutes) at low pressure will probably get you better gains. Total in-tube time is up to you, your level of cock conditioning to pumping, and your schedule.