If it is fiberglass it is fairly easy. Ours are fiberglass.

No, I believe it is a rubber/plastic it is very hard it is black in color if that helps at all.

Sometimes it is easier to drape an EPDM liner over the hard shell instead of trying to repair it.

My first pond was a hard kidney shaped shell purchased from a home improvement store.

It had developed a stress crack. I tried repairing it and every time it would crack again. I finally bought a piece of EPDM and lined the pond with it.

That was 8 years ago and we have since moved. The current owners are still using that pond and liner.

Hi
I would suspect if you don't improve the support base you'll keep having the same problem?? Of course if you improve the base enough for proper support you've spent twice as much as a liner pond??
You could use the liner over the shell but suspect the results would be rather ugly?? My advice would be to throw the shell away and place the liner in your revamped hole.
I'd bet the cost on a small pool would be comparable to repair.?? gary

When I lined the shell, I folded the edges under the lip of the shell and planted plants around the edge. Within one season, The plants hid the liner.

Hey all, thank you all so much for your efforts to get us out of the jamb. Its a pretty small pond and we were successful with patching a hole before but wanted to see if someone had some new tricks out there. I didn't want to invest in an entire tube of marine caulk so this time we purchased some Marine epoxy for underwater with some mesh tape for stability we will set it up and let it run for a while with out fish and then try some minnows out of the lake for a canary test. I will also put some more support under the pond as suggested. Again, thank you all for your help. We will fill with water tomorrow and see if were good to go.

Well happy to report that this 2 part epoxy mix from home depot seems to have done the trick. It's been up now 1 month and no more leaking. We did do a lot of work cleaning up around the edges where tree roots were pressing up on the back side and filled the bottom up with peanuts to give the bottom some cushion. Just wanted to let ya know incase someone was in same predicament. We have not tried fish yet tho. Still need to do that.

Well happy to report that this 2 part epoxy mix from home depot seems to have done the trick. It's been up now 1 month and no more leaking. We did do a lot of work cleaning up around the edges where tree roots were pressing up on the back side and filled the bottom up with peanuts to give the bottom some cushion. Just wanted to let ya know incase someone was in same predicament. We have not tried fish yet tho. Still need to do that.

Glad it is working out!

Hi
Hope it continues.lol. Of all the problems that water gardens have, what's worse than leaking?? good luck
gary