Interesting topic,
I have never used a lilly pipe but have used a experimented a lot. Right now I am using just the sheppards hook that came with my 2126. I am considering going back to the spraybar because it seems that I am getting a little bba in the front bottom of my tank. I think this is do to low flow low co2 in that area. Plants are overgrown right now.
I am not sure about lilly pipes but when I use the sheppards hook only(my cheap version of a lilly) my flow is very gentle. Set up like an ADA tank with sheppards hook on same side as filter intake. This does give me a circular pattern but a very slow one.
If i use the spraybar in the same arrangement I can cut my bar down in size a bit still getting a circular pattern with much more movement.
This is why I am always confused when people say a spray bar does not create as much flow as a pipe. It will create more flow than a pipe for me if you cut it down a little. Less holes for the water to exit from means a faster exit. The volume will remain the same no matter what configuration I assume but the velocity that the water exits is not. Am I wrong here? My plants tell me there is more flow by bending over more?
If you use a garden hose with a nozzle for example. If I set the water at a set flow and take nozzle off it isn't as fast and would not create as much flow. If I put the nozzle on and squeeze it the flow becomes much faster.
Pffft
I better stop thinking about this before my brain blows a gasket.
River