How do you keep fish out of a waterfall?

[glassbird]

I have two pre-formed ponds, one about a foot above the other. In-between is a waterfall, about two feet long. I have 9 larger comets that will be inhabiting these two ponds next year (they are not yet in these ponds...long story). The upper pond and the waterfall are new this year.

While working on the waterfall, a few days ago, I was surprised to discover that the upper pond DID contain fish, which probably arrived as eggs on the one plant that I bought this season. At least two of these "surprise fish" survived a trip down the falls while I was testing the pump! Today, I discovered 4 more inch-long babies in the upper pond. They are safe for now, as the pump is not on. BUT it makes me wonder...how do other people keep their fish from being swept down their waterfalls? It can't be good for their health!

[Flake]

you could probably block the lip of the waterfall with eggcrate or something similar, allowing water through but not fish.

[JPKeenan]

wondering if you can get some sort of plastic mesh for the intake of the falls, maybe even panty hose... But you would have to make sure they don't get clogged up or else you might burn the motor in the pump out.

[glassbird]

I was thinking about some sort of mesh across the lip...there is a product called "plastic canvas" that crafters use with yarn for decorative objects. I have some on hand already (in black) that I used when making a filter box. The downside is that the holes are very small. No fish will get thru, but it won't take much to clog it up. The roots of one water hyacinth up aqainst the mesh would be a disaster...

Egg crate would not clog, but the smaller fish would go right thru. I am thinking that a combination of the two might work...

Put the canvas mesh across the lip of the upper pond that spills into the falls, and put a section of egg crate across the pond about a foot away from the lip, to hold back the floating plants. As long as I am carefull to keep the floaters on the right side of the egg crate barrier, it might work. I experimented today by siliconing a strip of canvas mesh across the lip. I am not sure that the silicon is going to hold, but I will test it in the morning. And I will need to find black egg crate, so it won't be visible. Once the fish are too big to fit thru the egg crate, the plastic mesh could be removed, maybe.

Any other thoughts will be welcome!

[bmg07]

thats a very good idea