Might be better to stand the question on it's head and ask those who do
water changes "what do you think they achieve". I don't need to remove
NO3 (It varies between 0 & 5ppm) or PO4 or anything else I can think of
right now. If adding trace elements is your reason, then you're
assuming that the salt mix you buy has the correct trace elements in it
(Some don't event get the Ca & alk. right).

I have been arguing with these nuckleheads for about 2-weeks regarding
unnecessary water changes. I have received 3-reasons that they do them.

1) In order to add trace elements/remove nitrate.
2) It's enjoyable
3) Because coral release toxic chemicals into the water ??

I think the real reason they do it is for a lack of understanding at the
chemical/biological level. It is easier for them to do a water change than
to grasp what is going on in their tank at a biological level.


BTW: It's not laziness either, I also have 4 FW tanks & they get 20%
changed every 2 weeks. Anyone got any live rock that works in FW?