Is it safe for me to dissolve my med in water to wean myself off it?

I'm taking Geodon, and ive been opening up the capsules and pouring half of the powder out. I'm already taking the lowest dosage pill - 20 mg. So instead of pouring half out and just hoping im taking half, should i dissolve it in 100 mL water and just drink 50 mL of that water? But i was thinking this might not be safe. I heard people do it with valium, but maybe its specific to that pill.

Please if anyone could help me out that would be great.

He already told me to open up the capsule and do that, but i was thinking that dissolving it in water is an easier way to get half, or one fourth, etc. of a pill