I am all for owning your own RODI. And starting with live rock was a good call IMO. Hopefully it has all kinds of good microbial stuff in it.
As to "high" nitrates at this point you don't need to worry or intervene.
Have you tested for NO2 (nitrites)? If they are not yet zero, they will throw off a nitrate kit. Still, not a problem. The bacterial colony you started with to process the ammonia into NO2 (nitrites) will quickly develop the capacity to process NO2 to NO3 (nitrates) and ultimately NO3 into nitrogen. Poof. It is pretty cool, right?
Just manage the temp and salinity, and let a few billion years of biological evolution do its thing. IMO, interventions more often serve to set back the maturation process more than accelerate it.
As to "high" nitrates at this point you don't need to worry or intervene.
Have you tested for NO2 (nitrites)? If they are not yet zero, they will throw off a nitrate kit. Still, not a problem. The bacterial colony you started with to process the ammonia into NO2 (nitrites) will quickly develop the capacity to process NO2 to NO3 (nitrates) and ultimately NO3 into nitrogen. Poof. It is pretty cool, right?
Just manage the temp and salinity, and let a few billion years of biological evolution do its thing. IMO, interventions more often serve to set back the maturation process more than accelerate it.


