We have a large koi pond, it's very deep and we have good healthy fish. The pond and the large filter system work very well. Both pond and waterfall are fibreglassed. However, the waterfall is leaking and so it is not connected at the moment. My husband doesn't want to use fibreglass because he has a bad chest and doesn't want to use it to repair the waterfall. Does anyone know of a substitute to fibreglass that is safe for my husband to use and very safe also for the fish?

We live in the UK.

Your comments would be much appreciated.