Nitrate Sponge

[idgy]

Worth using or just trouble?

 

[Krish]

Never used one. Not really sure :doubt:

 

[clayswim]

Normally they just sit there and grow nitrifying bacteria; without actually removing much for nitrates (they can actually make the problem worse sometimes). It's better to do it the old-fashioned way. Water changes to remove what's already there; and live rocks and possibly sand to keep them low.

Clayton