It entirely depends on what you’re keeping in the tank.
This isn’t possible. One of your readings is incorrect, and I’d assume it’s probably the TDS. Are you using a TDS meter to test that?
To elaborate - when you test GH and KH with the API kit, you are testing for dGH and dKH. The d stands for degree. One degree of hardness - GH or KH - is equivalent to 17.9ppm.
Now, KH and GH both contribute to your TDS, your total dissolved solids. So if we have 17.9 * 11 GH and 17.9 * 5 KH, that’s 197ppm GH and 90ppm KH. Which, added together, equals 287ppm. This value should be included within the TDS, and therefore the TDS value should probably be above 300 (due to other dissolved minerals and such that aren’t recorded in GH and KH tests).
Hope that’s helpful.