Daphne, I know there are nontoxic sealants used for leak repair in fishponds...maybe an inquiry over on the Ponds Forum will be your best bet for a good recommendation. I've used a clear non-toxic aquarium sealant on an indoor item, but you'll need something to withstand heat/cold outside. josh

Here is a link that might be useful: Pond Forum

I had a concrete gargoyle that had both wings broken off, one in several pieces. Got some crack repair mix (I think it was vinyl reinfourced concrete mix in a small plastic can) at home depot and glued it back together thinking it would never hold. Been 4 years...

Call Aquatic Gardens on Hwy 280 in Greystone area or Birmingham @ 205-995-9466. That is the business they are in - water gardens and fountains.

Try veritex patch. This is the coolest stuff. I have some and am repairing all sorts of things around my house with it. It's better than duct tape. The adhesive actually gets stronger as the weather is cooler. So it should work for your leak in the bowl. hmmm, Your surface would have to be smooth though.