MyPond MS300 Marine Sealant, Window Sealer, Pond Sealer for Leaks Concrete Glass Metal, MS Polymer Adhesive 4x Stronger than Aquarium Silicone Caulking, Black Pond Liner Marine Adhesive Sealant, 300ml

Quite awkward to work with, it sticks like mad to anything it touches, other than where you want it to stick or course. Cleaning it off your skin and nails afterwards is a challenge! But it cures very quickly even in cold weather and underwater and cured my leaky pond problems.

Great product. Really does what you hope it will. It is very good at fixing pond linersBUTI have to take off a star becauseNo matter how careful you are it will get on something that you don't want it too.And anything that touches that, or touches the thing that touched thatAnd it's impossible to get off.

Big rip in new pond liner below the water line, used this and fixed - very satisfied

This is a great product. I used it to reseal an aquarium on top of the original sealant and have no doubt that the aquarium will now last for many more years.

It fixed a hole in my pond. I had tried other methods but with no success. I used it about six months ago and the pond no longer leaks. Great stuff although a bit messy.

Bit messy to use wear gloves but so far has done an excellent job would recommend

Very messy and very difficult to get off your hands. It will stick to anything it touches permanently so make sure you are wearing old clothes. I wish there was a warning about this on the product.

Not cheap, this stuff, but when used as directed it successfully seals cracks in concrete ponds. It is easy enough to use and will cure underwater but the surfaces need to be absolutely dry before application, otherwise it doesn’t adhere. The instruction should be followed not to try and flatten the bead of sealant too much if at all. A thin bead seems to work best.