Filter Floss vs. Flow

so i have two biocubes. I have removed the tab between chamber 1 and chamber 2 to increase flow. This is where i normally put filter floss. Is it better to force all of the water through the filter floss or just some? I had been forcing all of it through but my pumps were running dry fast because the tank level would rise as the filter floss gathered detritus. This also forced me to top off more often because of the issue with flow. Topping off more often was a good way to maintain salinity levels;D, which isn't a bad thing. I was just wondering how others handled the situation and why?

 

If you are using the floss to polish your water then you need to force flow through it, just change it often, every week or sooner.