I have had an otter in y pond lazt night lwhick has killed three of my koi I havE had them for over twernty years sp I aM REALLY PEED OFF the 4500 gallon pond is netter and is in ground and three feet above Does anyone know if I get some galvanised metal netting would this prove detrimental to the remainign fish. My two largest who r over 35 are undamaged but the three remainign have damage Any suggestions as to what I can add to prevent disease without affecting my filters

YOur input wud be appreciated

Galvanised metal is zinc which is toxic to koi.
However if placed above the pond the level is likely to be minimal and a possible short term arrangement that is better than the otters. Maybe then identify a better permanent solution.
Incidentally where are you based so we might warn other koi keepers?

Click the link below for YORKSHIRE KOI SOCIETY YouTube we will be regularly making short videos Tony https://www.youtube.com/playlist?list=PL9Tw9dIe3WGye7_JNvvflzY5_nYIiwRGj

Sorry to hear this, otters are a bought are once they find somewhere with easy targets.
May be worth rigging some electric fencing around your pond.

Laura