would this pond rebuild work?


Black Skirt Tetra
Original poster
Jul 9, 2013
question, can you build a liner pond on top of an existing pond?
I have a huge long skinny pond, it came with our house.
the pond is a liner, with large rocks around it and in it. it has shelves convenient for heron to sit on and eat the fish (through the net they try!)
the pond has one deep top pond with a waterfall filter dumping into it, then it goes into a lower waterfall to a lower pond that is long and skinny and only about 3 ft deep on the bottom pond part. when i try to keep the fish in the deeper upper pond, each spring they jump down the waterfall to the lower, shallower, pond. on the way some get eaten by birds waiting as they are exposed at that time. now. my Koi, since i keep it netted year round, have now grown big, huge. too big for one more winter in that shallow pond.
so that is my current situation.
what i want to do,
I am thinking i put the fish in the upper pond and run that alone this spring. i empty the bottom pond, take out all the rocks. rebuild the sides bigger and higher up, with cider block faced in stone to match the patio. then i put a liner in. the hook up the water fall filter to the new pond in the old pond and kill off the extra pond. now, question, can you build a liner pond on top of an existing pond? do i need to fill sand in the bottom of the old liner to make sure the new one goes on a very soft surface? has anyone done this? i want my fish in a deep body of water. i am more concerned of fish health and safety than the look... its fun having the natural water feature as it is but its not the best environment for my fishes :)

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MFK Member
May 15, 2007
Clean out bottom pond build your wall around it, a new liner won't cause any problems as long as nothing sharp is under it. Deeper pond should be great for your fish. Make sure you use a good underlay


MFK Member
Apr 2, 2005
Beavercreek Ohio
A old liner in the bottom will not hurt anything but it may be easier to take it out than work around it. while you are doing all this you may want to install a bottom drain and pipe to attach to your filter and not put rocks back in the bottom. It makes maintenance easier and your fish will do better.