The electronic devices are a lot more work than the test kits. I have a PH
and an Ammonia one. The ph has to be re-calibrated every few weeks, and if
the probe dries out, you need to get a new one (40 dollars for that).. The
ammonia one is only good for so long. I dumped the electronic one for this
one:

Looks good shame they don't ship abroad though.