Flow Meter

[JRPYL]

Looking for a flow meter with a 1 inch in/outlet that rates flow as low as 75 gph. The 1 inch Neptune only goes as low 150 gph. The 1/2 inch one goes that low but only up to 250 or so.
Im installing a Pentiar 25 watt UV. The flow for Protoazoz is suggested to be at 79 gph with a 131 gph max and suggested 472 gph with 788 max for algae and bacteria.
See some guys in Australia use this Rotameter... thinking about trying it just concerned about the metal rod. It's stainless so I'm thinking it will be fine.
Or taking suggestions on any 1 inch flow meter out there that goes as low as 79 or so.

TIA

 

[KrisReef]

A bucket on the outflow is the most reliable method to measure the flow rate. A gallon o minute is 60gph, and a 5 gallon bucket filling in 4.5 minutes would be a reasonable estimate (without doing any fancy calculations) of 70 gallons per hour. A little slower should increase the kill rate and not greatly reduce the volume treated.

 

[JRPYL]

That is an option for sure.
Closed loop hard piped into bulkheads in to the back top of the tank. Didn't want to reach in an put a hose on if I wanted to change the flow rate.