First you must determine if the readings are indeed false. Keep in mind that the sonar spreads in a triangular fashion as it travels towards the bottom and can cover a great deal of distance the deeper the water gets (the operators manual illustrates the coverage area). A solid row of fish may indicate a single fish being detected within the coverage area. In certain conditions where the weed grows off the bottom greater than 10% of the total depth of the water, a solid row of fish may be indicated. Under this circumstance, adjust the sensitivity to eliminate the weed readings, or condition yourself to understand what you are looking at. Keep in mind that a lot of prey are ambush feeders and may use the weed as cover; fishing your bait just above this weed layer will produce the best results.