What ever kit you go with use a trusted lfs to validate your test results. Personally I used 2 stores to validate my results to be sure. API for the basics is fine, after a cycle you don't really need to check NH3 or NO2 often, only pH and NO3. I went with the Hanna PO4 - works great. For Mg, Ca and KH I went with the red sea reef foundation. A little pricey but easy to use.