Advice needed

[tkelich]

I have a very large pond and have raised 10 gold fish and two alge sharkies for about 2 years. About 4 days ago, all of my fish disappeared. They used to come out when fed and I would count them to make sure all of them were there. All of a sudden one of them came out from under the liner flap and darted around then disappeared. I thought I saw a new baby, but even my sharks are hiding. What could be happening? The weather is warmer with very cold nights but my fish have been in a stable environement for over two years. The only thing I did was clean my filters, which I normally do. Any thoughts?? These are my pets and I don't want to lose them.

[madagascariensis]

where do you live? in the assumption that this is an outdoor pond, a predatory animal such as(here it really depends where you live) raccoon, heron or cat could have been the culprit.
if it is a bird then you will likely find no trace of fish whatsoever, but if it was a mammal then there will be bits of scales, fins, heads, guts, bones scattered all around the pond upon close inspection.

[Sandz]

While its warming up a bit, you could have cleaned the filter a bit to well and lost a lot of bb... Thats my main thought.

[luke-ns]

i cant see it being anything to do with the filter being cleaned if its something you usually do, yes over cleaning will kill all your good bacteria but goldfish can basically with stand any water very very hearty.

id agree with madagascar with it probably being a bird or cat.