All depends 100% on whats in that water..
Without having a full chemical analysis done we typically use a TDS meter and shoot for 0 TDS... But many have used tap water for years... (but thats just luck that their tap is clean enough)..
I dont think the tapwater defenders are thinking it through.
According to WHO data, basically all tapwater has levels of copper in it that are nearly toxic for most marine animals. Of course they do -- all tapwater goes through copper pipes, regardless of whether its city water or well water.
I suspect everyone using tapwater for their tanks is suffering a gradual buildup of copper in their systems that depending on their water change schedule and initial concentrations, will eventually become a problem.
Copper is so toxic, I wouldnt think of using water that came from a copper pipe in a fish tank. Its toxic at levels we cant easily detect with home tests even if we were testing for it.
Well water goes through copper pipes just like city water. Its entirely possible theres someone out there with negligibly low Cu levels in their tapwater. I doubt it but cant rule it out.
All I'm saying is theres no reason in principle why well water would be Cu free. I'm on a well and wouldnt dream of putting that stuff in my tank![]()
I dont think the tapwater defenders are thinking it through.
Copper is so toxic, I wouldnt think of using water that came from a copper pipe in a fish tank. Its toxic at levels we cant easily detect with home tests even if we were testing for it.