I'm not Rob, but as a long time caster I would like to join in.
Back in the late 50's, early 60's, I used a Bottom Pour (which were very expensive back then) and I "used" to empty the pot after ever casting, I only empty the pot now when the melt gets low, so I can clean it.
As Rob stated, I've never met a bottom pour pot yet that didn't leak, From a little bit to a hard to manage leak!
Personally, I seldom empty the pot anymore unless I'm going to change hardness levels of my melt, which I seldom do anymore since I shoot mostly pure lead in both my C&B Revolvers and my Muzzleloaders.
My advice to every new caster is; First off, be safe!
Water is NOT your friend. Keep a safe distance from water, along with wet or damp items, even a drop of sweat from your brow, can cause a bit of excitement if it hits the molten lead.
Wear safe clothing, including gloves and eye protection.
And likely as important as anything, is reading. Read everything you can on casting, and never be afraid to ask questions, lots of questions!
Remember, the only dumb question ever, is the one that is not asked!
Respectfully, Russ...