Unknown goldfish death!

[pattyfurg]

So I visited my grandma and she has a huge pond with some goldfish. Recently my grandad put food in for the water lilies and 4 fish died.
Iv transferred them to another pond now but could the water lily food have killed the fish?

 

[Mumma.of.two]

It could have depending on the ingredients. May have caused an ammonia spike or something.

 

[PHP]

Most likely so.

What type of food was it? Do you happen to have the brand name?