Hi all! I have been a freshwater hobbyist for a while and I have recently gotten in to the marine and reef side. I was a LFS lurker for a long time and I did a lot of research before I ventured down this path. I have a small reef tank (Bioucube 14). I have modified the second chamber and built my own media rack. The media rack has Chemipure Elite, some live rock, and Purigen along with floss and a sponge. I also purchased the Biocube protein skimmer... I know a lot of people do not like it, but after a lot of research, I decided to add it to chamber 1. I also do ~5 day water changes of ~3 gallons of water. The skimmer is still breaking in, but I like it so far. It pulls out a little bit of tea colored funk. Anyway... I was wondering if I should be topping off with RO/DI or saltwater from what is removed by the skimmer (which is not much daily). I do top off with RO/DI now for the skim and evaporation and I also monitor salinity with a refractometer and there does not seem to be much of a swing during the week. Thanks!