The flask would need support and I wanted to create something that looked like it belonged in a lab, not just a flask next to a pump. I used 2 Perspex disks cut from a sheet and heat-polished the edges as a base for both the pump and the flask. Held together with 4 stainless steel threaded rods. they were screwed into the top disk and bolted into the lower so that they could be removed if needed. 

To create the more "lab" like feel I used a small pump with hardline acrylic pipe and fittings directly below the flask to create the image that the flask was on a sort of bunsen burner. A flat passthrough fitting was screwed into the bottom of the flask which was then tightly screwed into the top acrylic disk with some added plumbers tape in areas to ensure no leaks. 

Once I was satisfied with the watertight seal and stability of the set up on a flat surface, I drilled out  a screwtop cap for the flask and added 2 more fittings, a hardtube fitting for inside the flask which was around 30mm from the passthrough in the bottom, so the liquid would not just fall into the flask directly and cause bubbles. A soft tube fitting was placed ontop of the screwtop for the intake of coolant. A quick disconnect fitting on the soft tube intake made it easy to disconnect, remove the screwcap and fill the reservoir. We ran a 36 Hour leak test and sent a number of images to the client to sign off on before sending it. I recommended some UV reactive coolant and where to buy Blacklight LED's to use in his build to give off a more "Mad Scientist" vibe.