I always used API before and I like them but recently bought the JBL liquid test and I find the colours a lot easier to distinguish, at least you can be certain when something isn't 0, unlike the API ammonia test which is hard to tell between 0 and 0.25ppm. I also have the JBL nitrIte, nitrAte, Gh and Kh tests and they are a breeze to use too. They come with nicer set of help tools like syringes, and other stuff, making it easier to test.
Other than that, home test aren't the most accurate to tell you the exact level, but can show you at least if there's something. The most known inaccurate tests are nitrAte tests, regardless of manufacturer.
AshleyT said:
How much are the master test kits an how long would it last?
Depends, it's written in the description of the particular test when you buy them but generally anything between 50-100 times for one test. You should try buying a master test kit as it works out cheaper than buying individually.
The Api master test kit is pretty cheap to buy from ebay. The JBL can be found cheap on
www.zooplus.de (it's in German but they deliver in Europe too)