The DANNCO Venturi is designed to be the 

Do's & Dont's

#5 Venturi

Do's

1) This Venturi is regulated for any pump, 12v or 110v between 500-800 GPH.  Anything less than a 500 GPH will not draft air into the water and anything over 800 GPH will create back pressure and cause water to be pushed out the airline

2) Place the Venturi as close to the