How do you tune the kalimba?
My job is to make sure every kalimba we ship is in tune, and to include a piece of paper with the specific notes it is supposed to be tuned to. If you take your kalimba seriously as a musical instrument, you will go out and spend $20 on an electronic tuner such as the one in the photo (there are many KORG models available and other brands as well - they all pretty much work great). Play one tine, and the electronic tuner displays the nearest note name, and tells you how far off your note is.
If you never play your kalimba and don't drop it, it will stay in tune for decades. After a month of daily playing, your kalimba will probably start to go out of tune, and adjusting the tuning will make it sound significantly better. One hour of playing really hard and loud (ie, if you are competing with hand drums) and you could probably stand a tuneup.
I played kalimba for about 10 years before I bought an electronic tuner, and I could not believe how good the kalimba suddenly sounded when it was really in tune! That is when I started to get really good.
We have detailed resources online to help you tune your kalimba.