Is this a pool spa or pond?
If the location of the leak is not somewhere where you care about looks then this is great:
Pond Armour. Its an epoxy -- really ugly but it seals.
Waterfalls and rocks often leak because the mortar tends to shrink. if you can go over the joints with some more mortar especially a fortified mortar then that may solve the problem
If the location of the leak is not somewhere where you care about looks then this is great:
Pond Armour. Its an epoxy -- really ugly but it seals.
Waterfalls and rocks often leak because the mortar tends to shrink. if you can go over the joints with some more mortar especially a fortified mortar then that may solve the problem