Hi, i'm Leo from Naples, Italy
Sorry for my poor english...
I'm 33 years old and married, working in a shop
Always i love the bullhead catfish, and I will try to breed them at my house ... in a small bonsai pond!
I hope I can help with your great experience, if it is feasible

Welcome Leo! We are very happy you found us. Do not worry about your english as it will be better than some of us

We would love to see pictures of your pond!

This is the "Lake"

Welcome to Pond Boss Leo77.

Very pretty pond Leo77.

It will be easy to spawn bullheads in your pond, bhut growing them to eating size will be very hard without a LOT of extra filtration to keep the water quality good.

As to where your leak is coming from, that could be hard to find. You cloud try to seal all of your rock with mortar or add a liner. I don't know much of anything else you could do to seal it.

I don't understand the problem of rocks ...

For filtration (i not have now, only a pump for waterfall) of 3500 liter of water, how big the filter?

My 18 goldfish may remain or be eaten? They are about 15 cm.
There are 1.000.000 ( )gambusia, I have to tell them goodbye?

A rock wall must be very well sealed to stop water seepage. ANY crack or crevice could leak. Most, what we call garden ponds, have a rubber or plastic liner put in to hold the water then the rocks are placed around the edges to look nicer.

If your rock is just stacked on a dirt bottom, the water will simply go under it and rise to the same level on both sides of the wall unless again, the rock is completely sealed and the bottom of the pond was compacted with clay AND the wall was compacted deeply and on both sides of the bottom.

Bullhead catfish will eat other fish. They will also eat their own babies. How big your filter will need to be depends on how many fish you have. More/bigger fish need more/bigger filtration.

Ok, but I do not have this problem because my pond is made with rubber and the rocks are in the towel, here is how it's done:
http://i53.tinypic.com/8wy62w.jpg
Then in a place I had a drain pipe for rain water; this pond is 5 years old and has never given problems of water infiltration

I opened a separate post to talk about my project.

Rex, the leaking rock wall was in another poster's thread. I believe Patspond was the poster.

Leo, welcome to the Pond Boss Forum from a a guy of northern Italian heritage!

LOL I realized that....no wonder Leo was a bit more confused than me.....

At least it wasn't your English that got him!

hallo!