how to low NO2 and NO3

[strager]

I have my tank about 2 month. But NO2 and NO3 are still high.
NO2 is about 0.1 and NO3 about 10. But NH4 was already 0 one month ago. I have changed water 3 times but did not work to low the NO2 and NO3. I have live rocks and sand in the tank. Are they the reason for this?

 

[bang guy]

How much waterflow do you have?

 

[strager]

Originally Posted by Bang Guy
How much waterflow do you have?
I have one 350 g.p.h. pump through wet/dry filter and anther 250 g.p.h. External Canister Filter. My tank is 40g.

 

[bang guy]

You have plenty of waterflow.
With the wet/dry your best option for lowering Nitrate is either an algae scrubber or large water changes. If you start to slowly remove the media in the wet/dry eventually the live rock will begin to process more Nitrate.
A good skimmer is a big help as well.

 

[strager]

I am thinking of adding a skimmer. Hope it helps.