25 lbs or so might not be out the question right now as you just got certified. Once you gain control of your breathing and buoyancy your weight should drop too. I prefer to put the majority of my weight on my hips and put a 2 lb weight on on the cam strap pockets. Another thing I found out too that it was tough getting below the surface initially but once I got down at depth the water pressure actually helped me stay down. I know when I first got certified I was wearing 21 or 22 lbs in a 5mm. After about 3 or 4 months of regular diving I was able to get it down to about 14 or 15 lbs.