Q: Hi - I just installed a pond measuring 19 feet by 18 feet (roughly oblong) with a flexible liner and is 30 inches deep. I live north of Boston, Massachusetts. I bought a pump that will circulate 1260 gal. but I calculated I have about 5,020 gal. in the pond. The pump lifts the water to a filtering bucket about five feet from the surface and then down a fall. The flow of the water down the fall is nice. I have a few questions:

1. Is the pump I puchased big enough? I plan to have a few fish (5-6) and plants, of course, but have not stocked anything yet............................................

2.I also plan to install another pond below the first that will be very long and thin. It will fill the space between two retaining walls. The measurements will be 3 1/2 feet across by 26 feet long and 18 inches deep. I want to pump the water from this smaller pond up to the upper wall and into a long pipe with a horizontal cut the length of a 10 foot pipe to create a sheet of water that will tumble over the wall into the small pond. I plan to purchase another pump so that there will be two separate systems as I thought the big pond flowing into the small pond would not be feasible because of potential flooding when the pump is not operating (for cleaning and unplanned power outages). Do you have any advice on the pump size to ensure the sheet of water effect. This effect is my primary goal in the small pond?

Any advise would be appreciated.
Thank you
J. L....

A: You will need a pump that will move around 12,000 gallons per hour. If a smooth sheet of water is needed you will need to use a pump that will move a little over 100 gallons of water per inch of the width of the waterfall. ie. A waterfall that is 14 inches in width requires a minimum pump of 1400 gallons of water per hour.

For your application you may want to use several pieces of pipe with the split in them. This will help ensure even pressure and water flow for the fall.
I hope that this is helpful. That is a big pump.

Thank you

Scott Bates