How important is it to not use tap water for carnivorous plants? e.g. is it a guideline or a hard rule?
I have seen several answers on here saying not to, but I have had a venus fly trap for 3-4 years so far and have only used tap water and it seems happy and healthy with lots of traps, it produces a flower stalk every year with boring flowers on it and eats lots of flies. I have another three carnivorous plants that I don't know the names of that I have only had 2 years, but they also seem healthy. This seems to contradict the advice.
Also, none of the plant labels or instructions that came with them mention this tap water issue, and this company seems to be the only one supplying any of the garden shops with carnivorous plants (although that is not a guarantee that they know what they are doing).
Should I expect them to keel over sometime soon, or is the fact they have survived this long evidence of the tap water being ok (not all tap water is the same after all, maybe ours is less bad??)