I agree that the API nitrate test is very reliable and readable (compared to Salifert) - along with being much cheaper. I have one API kit that is over 5 years old and still giving accurate nirtrate readings (confirmed with Salifert, the LFS, and my new API kit). I also think the API calcium test is great - easier to use and read, just as accurate and much cheaper than Seachem at least. On the other hand, I've found the API phosphate kit useless and Salifert much better. I guess each company's test kits have individual strengths and weaknesses. I've spent a fortune learning this over the years!
