"This is a much more economical way of testing your water than buying test strips for each substance. You dip it and read 30 & 60 seconds later.
You may also want to find test strips for Ammonia & Chlorine as the 5 in 1 don't test for these.
Also, if you are trying to micro-manage some of this, you'll want a more accurate and precise way of testing. Sometimes its hard to tell exactly which color a block is.
But for most people just trying to keep track of general where their aquarium is at, these are great."