kit. I had to buy a combo one, because the lfs gave me four separate boxes for each test. It was a pain to open each one up, do the test and then check the result and put it back in the box. It was more hassle than it was worth.
The one I got is a basic saltwater test kit. It has a tray inside that holds the test tubes and each bottle of solution. While I am doing one test, I can wait for the others to sit for the 5 minutes. It is really easy for me, but since I am new to this hobby, I would definitely use what the majority uses. Good luck!!!
Patti