b0ogger wrote:
It is possible that aquarium water contains low boiling trace organics that
would also distill over, I'm not sure.

I suppose it is possible. If there were any ammonia in the tank I
guess that might boil off first. Technically, though, anything with a
lower boiling point would boil off first at whatever temperature these
trace organics boil at, then there would be a period where nothing
boils off as the mixture heats up (all energy injected to the system
while anything is boiling would go towards the phase transition and not
temperature change) and nothing boils off. Therefore, you could just
discard anything that the distiller produces before the chamber reaches
100 deg C. Of course, that is even more complicated.

He would be better off collecting rain water and distilling it.

Assuming that there is enough rain. I think there tends to be a
correlation between areas on the planet that don't have much rain and
areas where water consumption is restricted.

How would you reuse the salt?
It would be next to impossible to separate the water soluble organic crap
from the salt.

I don't know. I did not mean to suggest that the salt would be
reusable. I was thinking of this as an exercise in water conservation.
If you don't have access to water, but you do have access to things
like electricity and salt mix, and you're somehow in this situation
where you need to have fresh water in order to keep your exotic marine
animals alive, distillation is probably the answer.

On the other hand, I'm sure there are ways to separate the bad organics
from the good minerals and reuse your salt mix as well, but it would
probably require a pretty sophisticated chem lab and maybe a few grad
students.

Au contraire! This subject is the very answer to his problem. No water
changes = ultimate water conservation.

That's true, though I think such a discussion might be better placed
under a topic with the title "Amazing No Water Change Method of Reef
Keeping." Or maybe, "Water Changes: Who Needs Them?" Or even, "Pros
and Cons of Water Changes."

Blake.