I haven't added water to my tank yet as I'm still gathering pieces, but I have a salt question. A couple of threads I've read indicated that you don't increase salt content at the DT or the sump. Just how then do you increase it? For example, if I bought sea water from the fish store (most sell water directly from the ocean) and it isn't at the correct level how would you go about increasing/decreasing salinity? I figure to decrease you would just add ro water a little at a time until your level is correct. but what is the best way to increase it?