Convert your mag drive pond pump to an aerating, recirulating pump with Fractionating Impellers.
Designed specifically for use in hydroponic applications, uses front-mount adjustable venturi inlet and a powerful ceramic/magnetic aerating impeller with an aerating tube with noise-suppressing muffler. 

*Attention* these work together as a unit so, You Must Purchase BOTH, Venturi Assembly AND Impeller Assembly!  

Venturi Assembly: 

Sup16505: for Mag drive pumps 250,350, 500 & 700

Sup16705: for Mag drive pumps 950,1200, & 1800 

Fractionating Impeller Assembly: 

Sup16555: for 250 gph pump 

Sup16575: for 350/500 gph pumps 

Sup16585: for 700 gph pump 

Sup16745: for 950 gph pump 

Sup16755: for 1200 gph pump 

Sup16775: for 1800 gph pump