Nitrates high

[fisherman2]

Hey i currently have a 12g nano cube with nothing but lr, a jellyfish, and some hermits that has extremely high nitrates.My other 55G has high nitrates too. why is this. any help would be greatly appreciated.

 

[milomlo]

Have u tested the water u use?

 

[fisherman2]

yeah the water is ro and is has 0 nitrates.

 

[laddy]

How old are the tanks?
What kind of biological/mechanical filtration are you using?

 

[ophiura]

What is "extremely high?"
What test kits do you use, and have you verified with another kit?
Water changes?
Feeding rate?