Fw Watercress Sump

[Matthew5664]

I have a problem with NO3 in the water where I live 30-40mg/l and I was reeding in this months PKF that people use watercree in pond filters as a nutriant exporting plant. My Question is could I use it in my tank with the help of a sump tank growing the stuff? Could do it in the same way as a reef tank uses a ref with macro algea in it?

What do you think?

 

[andywg]

That, or duckweed would work well.

You can do it with FW algae. If you can generate a system where the algae grows at a sufficient rate (normally through screens over which water runs) then they can even replace your normal filtration.