I am once again turning to the 'source of all knowledge'....

I need to upgrade my test kit and am going to try to cover all parameters so
please could you let me know which parameters I should be testing?

I know of these - am I missing any?
temp
ph
water hardness - is there another term for this?
ammonia
nitrite
nitrate

Thank-you
PS - some background:
Inherited pond which I wasn't that keen on, looked untidy and considered
filling it in and turfing over as there wasn't much sign of life. A few
weeks later having cleaned it out and tidied up, replaced filters & pump
etc. I've found some very grateful fish, a few frogs and now want a bigger
one.......