I can't speak to the bulk tank method, as my work area was always too far from the nearest "exit" to safely have the tank outside with the hose extending inside...even with the longest hose offered!
Nevertheless, I ALWAYS, ALWAYS, ALWAYS use the Yellow Canister "MapPro" purchased from Home Depo - the 1 lb. canisters - and have had wonderful success with them!
Now yes, I know it's more expensive.
But for me at least - since I was doing so much murrini production work - it was very important that after creating a design for 2 1/2 to 3 1/2 hours, I didn't end up with an unusable scum coating on my clear surround so common in my murrini designs...
You may want to purchase one or two Yellow MapPro 1 lb. Canisters and just give it a try to see if that helps to solve the problem....
~De