Option 1 would be to install a complete new drain either with or with out air option 2 buy a none aerated bottom drain and retro fit the lid section to the existing this would involve using a small section of pipe that fits the diameter of the stem that s on the bottom bottom drain cover and sticking it in place in the centre of the existing drain leave it for 24hrs before install the bottom drain cover with a 10 15mm gap from the pond bottom and sticking that in place with some.
Koi pond bottom drain blocked.
The ponds bottom should be bowled to this location with a decent slope this causes debris to move towards the drain via gravity.
Bottom drains in a pond usually work along with the filtration system to eliminate sediment and keep the water clean for the koi.
For liner ponds remove dirt around bottom drain pipe 6 deep with at least a 9 radius.
A pop bottle of about the same diameter as the pipe and stuck securely on the end of a broom stale makes an ideal plunger and would shift anything.
A general point with blocked bottom drains.
Install the bottom drain bulkhead fitting 1 below the pond bottom surface.
Even for the smallest of koi ponds we always recommend a 4 pipe on the bottom drain out take which connects to your settlement environment as this will allow for much larger debris to move trough the pipe without hindrance.
Sediment settles at the bottom and the force of the water pushes.
A hole to house the drain is dug in the deepest section of the pond.
But basically my bottom drain got clogged because of the fish and my bog.
A trench is also dug which leads to the settlement tank this houses the flex hose or pipe which leads to your vortex.
Mine feeds into my pump sump so the pipe is open in the bottom of the sump.
Klassic koi the big pond company.
Fortunately i ve never had to use it.
An alternative to installing bottom drains is to remove the fish from the pond drain it wash the pond put clean water and then place back the fish to the pond.
Let the concrete dry install liner and then place drain cover on liner over pipe opening.