If they will keep coming as you raise it, keep it going until they decide they wont go any farther. The distance they travel will change from day to day, but the general rule is keep doing what you were doing to get them interested in the first place. In most cases, you don't want to change your presentation just because you see a fish on the flasher. Ive had perch come up 4 to 5 feet before they would decide to eat or head back to the bottom. Just try to keep it within "tasting" distance just off the tips of their snouts. A slow game of keep away.