I have a 20 long that I'm about to set up. The tank is so long I wanted to get some flow from side to side. I used 2 AC
ext tubes, 5/8 ID clear flex tubing, suction cup heater holders, 5/8 elbows, and 5/8 blue rigid pipe from Home Depot. Not sure what kind of pipe the blue stuff is but it's a thinner wall than PVC
and it's not as ugly. The AC
ext tubes fit so tightly into the clear tubing so I sanded the ext tubes so they would slide on a little easier. Then while the tubes were on the tubing I boiled the ends of the clear tubing so it flared them out a bit. That makes it easier to take apart and put together later. All I need is a pre filter sponge on the end. I may get the tank and stand out of storage and bring it home next week.