When adding salt you do not want to add so much that you actually have salt crystals. A saturated salt solution (salt and water) should be used. Saturation is the point at which the water can hold no more dissolved salt. If more salt is added it will cystalize. If salt cystals are present, you are correct in saying they will clog the machine.As for the brine tank, it should never be completelty full. Remember brine is waste from the softening process and should be kept at a low level. If you have a lot of brine being produced this simply means that your water has a higher hardness. The brine tank should never go over half full and is usually at about 1/4. Why I dont really know; I think it is just an industry guideline that will reduce chances of overflowing.
