I don't want to get too involved in this thread but I will say this.
Lakes are constantly losing/regaining water. But lakes do not just lose water through evaporation. Most of the time lakes lose water through ways that also allows various minerals and other things to be lost as well such as through a small stream or by water seeping into ground water taking minerals and other things with it.
I know of only two instances (other than the oceans) where water is only lost by evaporation. And those are the Great Salt Lake and also the Dead Sea (not exactly a lake but same Idea) neither of the bodies of water are capable of supporting aquatic life.
now that I am reading this thread I have found a post that clearly illustrates one other point I was hoping to find brought out.
all who have seen salt creep on their tanks, or lime and calcium build up please put up their hands.:thm:
Those 3 substances can not be removed without waterchanges and if you wish your fish to truly live to their full potential you will do water changes. By this I mean not 1-5 years rather 10-30 years. If you think to laugh at this think again for there is a person in britain who had a 35+ year old goldfish. As well my west african lungfish will live a lot longer than that.
I will not abdicate MY RESPONSIBILITY AND OBLIGATION to make sure I provide the utmost in quality living space for the fish I have chosen to care for as well as enjoy!!! :werd: