Everyone has given a good short explanation of Ground Balancing, it is a good option to have on the detector as soil, mineralization and targets react differently when wet or dry. You should be able to get the instructions from the internet or post the brand name and model here, maybe someone has used it and can offer help! Get out and use that borrowed detector, if you are still not sure about the hobby afterwards then consider a Bounty Hunter for $100.00. If you are content with the hobby then get that Ace 250 and it has a larger and smaller coil, just make sure you get the coil covers as they will help preserve your coils on that Ace. My friend has an Ace 250, great little machine and lightweight, he is hard on it and has cracked his stock coil twice and it is still ticking, LOL! If you are extatic about the hobby and have some extra cash, then consider a White's MXT, easy to use and is a very versatile machine, many coils available for this machine as well and make it a good choice! Just my opinion and let us know how you are going, just get out there and try it! HH, Mike