160ppm nitrate suggestions?

[daniella3d]

You should start dosing some carbon source but go slowly. It will take time to lower such huge amount of nitrates, it won't happen in one day. Dosing carbon will be the best way to go I think, for the future at least.

Maybe a reactor with biopellets, but again, go very slowly and a very small quantity to begin with.

A skimmer is a big must in this case.