W/C's and drop in SG

[scsi]

I think the point people are trying to make here is that your logic, regarding water changes, thus far is fatally flawed.
I haven't seen a light bulb go off over your head with respect to your first couple of really ummmm.... unconventional posts concerning SG and water changes.
Read between the lines..... you could do a 100% water change and not change the SG.........