Currently using Nyos nitrate test kit. Shows between 12 and 25 ppm. Tank has been set up for a little over a year no algae growing, but I am always concerned that an outbreak is right around the corner. Took a water sample to a LFS for a sanity test. They tested with API and used a Nyos nitrate test also. The API showed 0 and the Nyos showed 3 ppm. I noticed that the LFS did not put a lids on any of the test vials. Is this the wrong way to test? Are the lids just to keep water from coming out of the vial? Thanks for your time.