All soils have varying degrees of mineral content or "mineralization." Some, like in FL have almost none. Others, like some of those out west have high mineral concentrations. Typically, this is the result of igneous geologies, industrial activity or the inclusion of alkali/salts in the soil matrix. Another place this effect occurs is in the wet salt sand down at the seashore.
Regardless of the cause, this mineralization can mess with a detector by masking its ability to differentiate between the soil itself and targets buried within it. It has been compared to driving with high beams in a dense fog, where the intense reflected light from the fog blinds you. The same thing happens to your detector when the minerals reflect too much of the signal - your receiver circuits in the detector are overwhelmed. Ground balancing is one way to overcome this, by adjusting the detector to be neutral to the ground minerals. Then it doesnt "see" them and their effect is eliminated.
Some detectors do this balancing business automatically, using computer software to make constant adjustments as mineral concentrations vary. Essentially they are tracking with the ground minerals to overcome their effect. Other instruments require that you do this 'balancing act" manually, making the adjustments yourself.
Still other detectors have a ground balance that is preset, adjusted to work in a wide range of conditions. These are usually the lower end machines, although not always a bad thing in and of itself. The Ace 250 is one of these pre-set instruments, having neither an auto ground tracking or manual balance feature. You have to move up to the Garrett 1350 before you get an auto ground tracking ability, I believe.
Does not having a ground balance hurt. Probably not. TO know if you ARE being affected by them, follow Kenny's steps above and see.
