I was surprised to find them that high but I am also wondering about the wide ranges I was getting. I've never looked at nitrates before and have no idea as to their variability. I know, especially in agricultural area, seasonal variations can be large. Other kits are en route.
I am looking at some DI units right now. Can they be run 'on demand' or do they need a constant flow? The big ones I work around can just sit or whatever, as long as there is no biological activity. You just regenerate with caustic/sulfuric as needed.
I am going to construct an auto-leveler. How long can DI water sit in a bucket before it gets bug ridden or whatever?