If your tank fermenter is incorrect or you need to set a capacity on a new tank, you can update that by doing to the following:
Step by Step Guide
1. Go to Administration->Setup->Inventory->Warehouses
2. Find your warehouse/fermenter in Find mode (CTRL +F)
3.Bring up the User-Defined Fields (CTRL +SHIT + U)
4.Change the number in the Warehouse Capacity field and then click Update.