I personally like the Tetra liquid test kit because the colors are are easy to distinquish vs some others. Hagen has a good one but some of the colors are hard to tell. One of the better cheaper ones too are Aquarium Pharmacuticals. There all usually come with readings for Ammonia, Nitrite, Nitrate and ph. Sometimes they also come with GH and KH.
It has quite a few strips in to use. These can be doubled by cutting the strips lengthways with clean sissors. This is a little money saver which I use.
LOL I've got the Tetra test strips, they are crap It told me my nitrate was fine, took a sample to the shop, they said the normal was yellow. Mine was red
I don't rate them test strips by tetra either, but if a person hasn't got enough money to buy all the liquid tests in one go, it's better than nothing.
I use Jungle Quick Dip. They sell them at Dr. Foster and Smith. They test Nitrate, Nitrite, Hardness, Alkalinity, and pH. You get 100 in the bottle...and good idea about cutting them in half fishman...idk why I didn't think of that! I'm gonna start doing that from now on