I set the water level about 1/2 way up the first riser and let it settle for a while, then added the air and readjusted the water level to 1/2 way again. That was that ran great for three weeks that way until the store added more live rock to the tank and it went crazy and overflowed, but you shouldn't have that problem. The injector tube ended up being about 2" into the first riser, any higher and i couldn't control the washing machine effect.
Any more ?? fire away. Glad it works the first go, and again it looks very nice.
Clinton