Why do you want bigger nuts ? I know a girl that has big nuts - size 44DD's and they are "NUTS" ! LOL
I used my pump and pumped my nads for awhile, then they seem to have toooo much hang and I was sitting on them in the hot humid weather (more hang in the summer time?), so they just started to get in the way, under my ass (while sitting) and under my leg etc - so I quit pumping my balls.
As you get older, they will hang and get larger, then you will wish they were smaller ? LOLrofl