Mixing station reducing pump inlet size

[AaronFReef]

I know you’re not supposed to reduce pump inlet PVC sizes but my norwesco 100 gallon tanks come with 1-1/4” bulkheads and my just purchased Reeflo dart/snapper pump comes with 2” on its inlet. This must be common, but how is this best handled so as to reduce cavitation?

 

[Reefer Reboot]

The best way would be to increase the size of the bulkhead in the norwesco tank. If that's not possible then reduce the size of the outlet of the Reeflo to less than the size of the inlet to restrict the flow rate.

 

[DCR]

You can help overcome it by raising the Norwesco tank well above the pump. This will allow for more pressure drop in the suction piping through the 1-1/4" bulkhead. Ultimately you may have to throttle back on the discharge of the pump to reduce the flow rate and keep it from cavitating.