Originally Posted by bigk_54
Hello, Im about ready to buy a liquid test kit.
I was looking at the API one but I see some of them that are twice as much also test for GH and KH hardness, Iron, and CO2. Do I need to monitor those things and is it worth the money to get the better one?! Thanks!
The general and carbonate hardness could be helpful, but the iron and Co2 tests are more for dedicated planted tanks.
The gH and kH establish the pH in the tank. Establish in that the gH and kH especially keep the pH stable, which is of course what you want. That's what I mean is that having test kits for gH and kH is helpful, especially if your pH starts to fluctuate. A gH and kH kit would tell you why.
That said, it is ALWAYS right to buy the very best you can possibly afford in aquarium keeping. Going cheap almost always results in fish death.
The API test kits are pretty good, and contain top shelf hobby level reagents, so I'd suggest you go with them. You could spend a couple hundred dollars and get a set of laboratory-grade regents, or go whole hog and go with electronic meters to test pH, gh kh and many other parameters, and a colometer for the lab-grade reagents. Just depends on how serious you are about accurate readings, actually.
But a API setup is, as I said, pretty good for hobby-level testing. Were I to go to that level of testing, the API master kits would be what I'd buy.