am trying to post a photo

Can you cut in a valve between the pump and upper pond? Then use it to reduce the water flow and balance things out.

If you are correct with your diagnosis then can't you simply make the weir at the upper pool a little more broad?

(If you are correct and you're losing water at a low spot along the edge of the upper pool.)

It's that or raise the grade around the edge of the upper pool so to have a uniform edge (pool elevation) and not have any low spots.

It is obviously worth checking things out step by step. Mike has the least disruptive first step. If yu cut in a valve with a Y connection, you could then divert the possible excess back to the lower pond if needed. In any case a valve will prove OR NOT your "too slow spillway" and then you are done unless you feel like just lowering or widening the spillway.

However, in addition to a low spot elsewhere in the upper pond, there is a similar lower pond low edge possibility and a leak in the tubing; probably at a connector. It seems way to soon to rip things apart.

If a low upper edge seems possible, it would probably be wise to block the spillway with a solid object and 'great stuff' and fill the pond and see if the water goes down. Same for lower pond.

lets talk pond construction for your upper and lower pond design.

The lower pond should have a overflow pipe to control the max. water level. It should run to a drain or dry well 3-4 feet away from the pond. If you are using a skimmer box it is likely in there.

The water supply to the upper pond should be by way of a falls or hose above the water level so it will not syphon the pond empty when the pump is turned off. The spillway on the falls to the lower pond is the high level control for the upper pond.

The liners at the falls must overlap such that the upper one shingles over the lower and is wide enough to keep the falls from leaking at the sides.

If your pond meets these design considerations, simply turn off the pump for a day or two. If the water level goes down in either the upper or lower pond then look for a low edge in the pond that lost water. If the water level holds in both ponds, the problem may be ether a leak at the falls liner overlap or you are infract moving more water into the upper pond than the spillway can let out.

Falls do often leek due to water going under them in addition to over like we would all like them to.

If it is a flow issue, reduce the flow in with a valve or lower GPM pump or get the hammer and cold chisel out ;-(

Good luck!

Mike

My pond setup

Wonderful stream and clear pond you have there mike. Have you found like I have, that the stream does All your filtering for you? Lachancesare, you may have some stream there too, and some plants will catch some crud and filter things out.

Thanks chas045. It may help but I also have a skimmer on the left edge of the photo. It contains the pump, basket, overflow and filter material. In addition I have a bio-falls at the top of the stream with filter pads and balls. Combined it make for a very stable ecosystem with very little maintenance. I just empty the skimmer basket once a week and wash the filter pads once or twice a year. I also use salt in my water at 50 pounds per 1200 gallons. The fish don't get sick and it keeps algae under control. The plant maintenance is the only thing I need to keep after.

Mike

lachancesare,

How did you make out with your leak/flow problem? I am curious as to what you found and did to fix it.

Mike