Hear are some tips you should follow:

On the beach and in highly trashy sites always use Fixed Ground Balance and Beach DISC. After you become more familiar with the X5, then you may find that normal DISC can be used in these conditions.

Manual Ground Balance Instructions:

1) Set the SENS control to 8.
2) Set the Mode switch to All-Metal.
3) Set the Select switch to Manual GB.
4) Hold the coil up in the air (steady) and adjust the Threshold control for a
very low (slight) audio volume (this is very important).
5) Adjust the GB control fully clockwise.
6) Lower the search coil slowly to toward the ground (from 12 inches to 1 inch).
You should hear an increase in audio volume as the coil is lowered to the
ground.
7) Raise the search coil back up to 12 inches above the ground and adjust the GB
control 1/2 turn counter-clockwise.
8) Repeat steps 6 & 7 until the audio tone disappears as you lower the search
coil to the ground. (Note !!! this step is extremely IMPORTANT because if
the soil at the location you are trying to Ground Balance does not contain
iron mineralization then it is impossible to manually ground balance the
detector properly and Fixed GB should always be used in this situation).
It is the same thing as trying to ground balance to air.
9) After the point is found where the audio tone disappears, then readjust the
GB control clockwise slightly, until the audio tone is equal in volume when
slowly lowering and raising the search coil 1 to 4 inches off the ground. You
are now properly ground balanced to operate (search) in the All-Metal Mode,
but this is NOT the ground balance setting to be used for Discrimination
Mode.
10) If you desire to search in the Discrimination Mode, then adjust the GB
control 1/4 to 1/2 turn clockwise after steps 1 through 9 above have been
successfully completed. This is necessary to eliminate or greatly reduce
ground pick-up (noise).
11) Now, set the Mode switch to DISC and set the DISC control to 3.5 to 3.8. You are
now ready to search in the Discrimination Mode. If ground pick-up (noise)
appears (not iron trash signals) then adjust the GB slightly more clockwise.

For maximum depth, the SENS control can usually be increased from 8 to 8.5 or even 9 depending on the conditions at each location.

Troy