Nitrite And Nitrate

[Built2Prfctn]

Both the Nitrite and Nitrate are high in my tank.. I have treated it 3 times and it is still very high.. What can be causing this?? wat do i do>???

 

[WILDER]

How long has the tank been set up.
How often do you do a gravel vac and water change.
Clown loaches need 90 gal tanks.
What filter do you use.