AbyssalPlains
Contributor
Hi all, Newbie here. Please no flames. 
I bought a used doubles rig and started diving it this past weekend. I love it already and want to practice the relevant drills. For logistical reasons, my deco and advanced nitrox classes were done in singles, so I have to learn as I go along.
Question: When I do valve shutoffs and breathe down or purge my regs before a switch, is there a chance of getting water into the regs or the tanks? I really want to practice this stuff in the pool but not if there is a chance of getting water in my freshly inspected steel tanks.

I bought a used doubles rig and started diving it this past weekend. I love it already and want to practice the relevant drills. For logistical reasons, my deco and advanced nitrox classes were done in singles, so I have to learn as I go along.
Question: When I do valve shutoffs and breathe down or purge my regs before a switch, is there a chance of getting water into the regs or the tanks? I really want to practice this stuff in the pool but not if there is a chance of getting water in my freshly inspected steel tanks.