So my understanding of partial water changes each month is to help replace trace elements and such that comes naturally in the water from the salt mixes. I'm just thinkin outside the box here but would you still need the pwc's once or multiple times a month if you just add the trace elements weekly? Ive got a 5 gal bucket i use that has RO that has also a small amount of trace in it that i add daily to replace the evaporated water. I still do my pwc's once a month but was just questioning what i have been told and read about.