Well, to get it down to 1.026, you are going to have to replace around 30 gallons of your water with RO/DI top-off water. Easiest way is to do a few gallons at a time as you don't want to drop too fast. You will want to drop it over the course of a week or two I would think to be safe. Make sure you calibrate the refractometer every time you use it.