connections lines from 25lb propane tank to propane Hot water heater

Hello,

I have a 30 gallon propane hot water heater. It says 33,500 on the side. I assume that is the btu input from the propane tank.

I don't have a 100lb propane tank but I do have a few 20lb bbq propane tanks that I use for my canjun cookers.

I have a flare fitting on my hot water heater and I can't find a line to connect my 20lb tank.
I'll need a regulator also.

Any idea where I can find a line from my 20lb tank to my hot water heater?

Thanks for any help or links.

Slash

any RV store will have the regulator. its most likely standard flare propane fittings at the water tank.