You could try to learn Dry Jelqing if atmosphere is the problem.
I don’t think that you need Jelqs to gain length but Jelqs will probably help your body get accustomed to your new length. What I feel Jelqs did for me was stimulate the vascularization of my penis and help out with my EQ.
At the beginning of the month when I got some length I really had a hard time staying at full erection (I could only stay at like 90%). But now it’s getting easier and my penis has grown some new veins.
Start (04/11) - BPEL : 18 cm (7 1/8 in), EG (midshaft) : 14 cm (5.5 in)
08/11 - BPEL : 20 cm (7 1/8 in), EG (midshaft) : 14 cm (5.5 in), BPFSL 21.5 cm
Just hit a plateau >.< gotta go through it!