"bo0ger1" .@. wrote in message m...
So which tank will experience bigger difference in the ionic composition:
- the one you replenish 25% of water composition every month ?
- the one you replenish 10% of water composition every month ?
- the one you do not replenish used up ions at all ?

My point is that they ALL will experience a change in ionic composition.

The question was: Which one will experience BIGGER difference!
You pretend you did not notice or you really did not notice?