It sounds to me like you’re not quite neutral to begin with. The first thing I would do is go over the standard weight check test on the surface when you get in the pool. That should get you in the ball-park on weight and really won’t matter where it’s located. Once that’s done then you can shift the weight around and see where it is most comfortable when you are about horizontal in the water (20 deg or so). Most BCDs now have pockets for weights and I would recommend that or a weight belt as a starting point rather than on your tank but everyone’s different.
Your doing the right thing - get in the water and figure out what works so good job on that.
Best of luck!
SKuba Steve