Repairing concrete fish pond,

lacosa6, Jan 14, 4:09am
We have recently bought a new house and whilst clearing the gardens discovers a rather cool but very old congrete fish pond, we have cleand it and filled it (even though it has cracks and looks like someone has broken the bottom f it with a spade or something. How could we repair it?

ceebee2, Jan 15, 12:00am
Get a bag (small) of ready mixed grout / concrete. Follow instructions and fill the hole.
How big is the hole?

lacosa6, Jan 15, 4:09am
about the size of a soup bowl, will it bond with the existing concrete and be water tight?

sweet_rhianna, Jan 16, 9:57am
The fish pond at my parents place had a hole drilled into it. Dad concreted it but the pond would still leak. Ten years ago the solution was to paint on a sort of a membrane, wasn't very satisfactory. This last year the membrane failed and they found some expensive paint designed for waterproofing ponds and the like. Can't tell you how good it is because they are waiting for to cure at the moment.

sweet_rhianna, Jan 16, 10:03am
Also if you plan to populate with goldfish it's best for the fish not to mix the slow swimmers (double tailed or fan tails) with the speedy fish (comets & shubunkins) due to speed at getting the food. And ensure they have plenty of cover, about 80% if I recall correctly, which is why lilies are a good option. Good luck with your pond, I wish I could have a fish pond too.

devine-spark, Jan 16, 5:56pm
I have used that painted membrane and it is a good option. It is a little 'tar' like, thick and rubbery, and has a good seal. I would consider a long time before placing any fish in it though as it is pretty toxic.

ceebee2, Jun 8, 5:59pm
You can also line it with plastic sheet to water proof rather than expensive fillers. Once the water fills it will exert sufficient pressure to obtain a reasonable seal. It may leak a little but that wont hurt. rain will top it up naturally. And eventually sediment will also seal it.

Another thought is to get a can of butyl rubber in a spray can from Mitre10 / Bunnings / spray the new concrete, then place plastic membrane over it.