Does anyone know what the rusty color is that sticks to the liner of out door fish ponds?

Answer 1

Well it could be brown algae, which is common on outside ponds late in fall or even into opening the ponds in the spring.

It can also be just leaf matter that has left a ring on the liner of the pond.

Either way it poses no real harm to your fish. It should wipe off easily.

Answer 2

I think its called brown algea,I dont kinow how to get rid of it since I do not have a fish pond but the brown gunk on your ponds liner is called boown algea. rubberstampr

Answer 3

Do you use any products like Flourish to fertilize plants in your pond? These usually contain iron, which plants need, because aquatic environments are typically iron-deficient.

Check the contents of any such products you might use.

Answer 4

Its Iron Buildup