I’ve been reading some things from other sources stating that the constant use of tap water can kill your trees, with a build up of minerals.
True / false / only some trees? Does anyone collect rain water and if so, does it matter how long it sits? If it is stagnant etc? There is a very old tank in my yard filled with rain water, algae and probably baby mozzies

What do you guys do and how concerned should I be using tap water and liquid fert?
Thanks in advance and sorry if it’s already written somewhere else.