Pond fish
My first fish were the goldfish and koi I stocked my 300 gallon pond with.
They did great for about 5 years. Then they started dying off. And all the new fish I got died off rapidly, too. I gave up after another 3 or 4 years.
Later, when I decided to redo the pond (or else get rid of it) the first fish also got sick. I FINALLY realized that the 10 pound bag of flake food I was STILL using (now 10 years old) was killing off the fish I dumped that food.
My first fish were the goldfish and koi I stocked my 300 gallon pond with.
They did great for about 5 years. Then they started dying off. And all the new fish I got died off rapidly, too. I gave up after another 3 or 4 years.
Later, when I decided to redo the pond (or else get rid of it) the first fish also got sick. I FINALLY realized that the 10 pound bag of flake food I was STILL using (now 10 years old) was killing off the fish I dumped that food.