Fluid retention happens when the penis is under too much stress or pressure. This happens when you are restricted too long, whether it be pumping, hanging,
ads or any other tool that constricts blood flow. As far as pumping goes this happens at around the 5 minute mark and that is why
SRT uses the 5x5x3 routine, it eliminates the retention and brings greater tissue gains. If you are seeing water retention you need to adjust how long you are under pressure or constriction and correct the time.