Q. I understand using a water meter to measure the total gallonage of the pond and filters but I have no idea how to measure how many gallons per hour will be passing through the system so that I can control it..

A2. As an alternative to the measuring the time taken to fill a bucket etc. If you have an external pump, connect, with "T" joints etc, two pieces of clear vinyl tube as close to the pump inlet and outlet as is possible. Mount these tubes so that they 'stand' upright and side by side, switch the pump on and measure the difference in height of the water levels in these sight glasses. The difference is the "head" that the pump is having to develop to generate the flow. On the pump's flow chart look up that head up and the corresponding flowrate.

I have such a set up connected to my pump and this photo is of the sight glasses, the pump is off.

NOTE. If your pump is a submersible then you can dispense with the sight glass connected to the inlet and just measure from the water surface above the pump to the water level in the sight glass. You could use non transparent hose for this version of the 'experiment' and measure the height of the hose end, above the water surface over the pump, when the water JUST stops/starts trickling out of the 'sight glass hose'.

Posted by Sean 27.11.05.