<a href=showthread.php?s=&postid=12674676#post12674676 target=_blank>Originally posted</a> by dew2loud1
The alita's should be able to handle back pressure, so I personally used a john guest type of valve that just limited the alitas output to what I needed. Some say you should "bleed off" the extra air with an adjustable valve but that was very noisy in my case. Increased air will result in reduced water flow which should reduce turbulance, but its a very fine balance, too much and it will cause cavitation and burping of large bubbles.... You're also limited to what the 8" neck can handle as far as adjustment, it appears to be pretty tall so you've got some room for adjustment either way.