Kids upstairs, parents downstairs. How???

[Fedfire37]

I have a 2 tier pond with 2 goldfish and 4 Koi in the lower pond. The top pond overflows and cascades down rocks about 18". Yesterday my wife noticed we have a few baby fish in the upper pond. They appear to be baby Koi. My question is, how did they get up there? We tried keeping a few fish in the upper pond a couple months ago, but they all ended up going over the waterfall into the lower pond. Would it be possible for babies or eggs to survive a trip through a UV sterilizer and through a bio filter? I have a homemade biofilter from a small wastebasket which pours into the upper pond.

 

[sissy]

could frogs have carried some of the eggs up on there legs or could you have taken plants from the bottom pond to the top .Could eggs make it if they got sucked into the pump ?

 

[Fedfire37]

The pump is designed to accomodate larger debris but I can't fathom anything surviving a trip through a UV sterilizer and multiple layers of bio filtration. The frog theory is possible. I didn't even think about that. We've been raising a few bullfrog tadpoles that recently grew legs and went exploring. We haven't moved any plants in a while.

 

[Nepen]

I have similar experience. I just found a baby goldfish in a bog. The bog is about 30 feet away from the pond and filled with gravel, no egg would be able to pass through that. So for mine I think it came with the plants I got from Addy. Or could just be the frogs who did the deed in the pond and then went to the bog.

 

[MitchM]

Eggs come attatched to plants all the time.
That's how I got all my goldfish. It took quite a while before I spotted them swimming around as well.

 

[mrsclem]

My filters are filled with fry that made it thru the pumps. The little guys are tough!

 

[haver79]

I usually find a few babies in my filter when I clean it. The eggs make it through the pump and into the filter.

 

[freddie]

Same here, I find tadpoles swimming at the top of my skippy filter.