Re: how can you tell how hard water is?
Hello Jow,
There are tests available to test the general hardness (GH) of the water. They are often sold at pet stores/aquariums and often come with a test kits for carbonate hardness (KH), but the KH test kit is irrelevant- unless you really want to get complicated with the chemistry of water. Another way to check the GH of water is to perform a conductivity test. But this is just too much work and it involves the use of handheld probe tester.
If/when you do purchase a GH test kit, the recommended parameter should be roughly ~143.2ppm.
On a separate note, axolotls should never been housed in softwater (eg. distilled/deionised water). That is, water that either has no/little dissolved minerals (salts) in it; minerals are essential for osmoregulation. Efficient osmoregulation is required for the uptake/release of important ions.
A presumptive way to check whether you live in a place that has hard water is to observe the base of the kettle. If the kettle has developed limescale, it will most likely mean that the water is hard. Alternatively, you could contact your local water authority and have them confirm the relative hardness.
Hope that helps in some way :happy:
Jay.