Originally Posted by Tim_G
I have also heard that the machines from supermarkets ect are actually worse than tap water. I heard they are sterilizing the water through evaporation through copper coils and then collect the "purified" water in vats...
This is how distilled water / alcohol is made. It doesn't collect a lot of copper but it will get a tiny trace amount from the cooling process.
Originally Posted by jeffaquarius
To eliminate the possibility of tap water causing fish dying, I would suggest to get a TDS
meter and see how bad your tap water is. I still can't believe that the corals and inverts are healthy if water is suspected to be contaminated. They are supposed to be more sensitive to water quality than fish.
HM Digital Handheld TDS Meter w/ Thermometer
If you had pwc
and then all the fish died then yes I would suspect the tap water. Like you said you have been using same water for 9 months. It would take days and you would have noticed fish to be stressed out before they died and not just overnight. I still strongly believe you have MV.
I agree with you on the TDS
But as far as the fish dying from the water quality issue think of it this way. There could possibly be a contaminant in the water that effects a particular part of a fishes anatomy. The easiest example of something like this happening is Melafix and Labyrinth fish. It is potentially very deadly to any fish with a labyrinth organ but perfectly safe to all inverts, other fish, corals, and plants. Without a 100% chemical readout of everything in his water there is no way to rule out the water being an issue without doing a massive water change with water from a pure source.