Hey fishlore - I'm mixing my first ever batch of salt! Very exciting. However, I just measured the SG after letting it mix for a few hours, and my reading is lower than I thought it would be. Tropic Marin says to mix 1/2 cup per gallon to reach a SG of 1.026. I did that, and I'm reading 1.018. I checked the "precalibrated" refractometer using distilled water, and found that it was a bit off, so I just calibrated it before getting to the 1.018 reading. Am I doing something wrong? Do I need to wait longer? Or should I just slowly add more salt until I hit my desired SG of 1.025?