To convert units of measure from another standard unit of measure for tracking in the General Ledger, the Unit Weight and Product Density must be entered on the Product.
The Unit Weight is entered on the Profile tab at File / Open / Product / Profile. The measurement will be listed in Lbs/Inventory Unit. Typically, this information can be found on the product label or by manually weighing the product. If the Inventory Unit is set to gallons and the Unit Weight is 5, then the Unit Weight would be 5 Lbs/Gal.
The Product Density is entered on the Blend Setup tab of the Product. The Product Density can typically be found on the product label. Product Density will be listed in Lbs/Gal for liquid fertilizer or Lbs/Cubic Foot for dry fertilizer.
Assuming densities are entered as Lbs/Gal, the calculation to post Gallons as the G/L posting unit on the department is:
Inventory amt * wt in lbs / density