I use the screw in type on a piece of 1" schedule 40 pvc. I ordered them off ebay from cconly. I attached mine to some wood poles and have adjusted the height as my chickens have grown. I used a 55 gallon plastic drum I picked up for about $8 bucks. I think including the nipple waterers I might have $25 bucks in the whole thing. Works great because I have no nearby water source. I drag a water hose about 200 feet to fill the 55 gal. drum. Mine is gravity flow also. It last about a month with the 19 chickens I have on it. I'd say I have mine about 16-18" off the ground right now. But mine are mostly grown. I might have to raise it one more time because I notice my roos having to bend over some to reach it.