Filter problems

[glolite]

Our pond filter recently stopped working and was down for 2 weeks. The pond is 90.000 litres so water changes would probably do little to help. The ammonia readings are nil but nitrites up at 2.0 Will this have the same effect on coldwater fish as on tropical and if so is there anything I can do? There are 8 large English Koi in there plus assorted sizes of goldfish, rudd, roach and golden orf.

 

[black angel]

I'm no expert on ponds but i always thought you had to treat them like aquariums but on a vast scale. it seems your filter is cycling again and you may need to do those water changes to keep the nitrite down below 1. normally i would say add salt to help the fish through the nitrite level but you would need a huge amount and the plants and wildlife will probably suffer.

hope someone can help, good luck.

 

[glolite]

Arrrg! Thanks though. Looks like 2 cubic metres of water changes daily then.
That should keep me out of mischief for a while.