Running tally

[Josephlesane]

I am trying to keep track of a 200 gallon Nitrogen tank. I need to be able to input a daily value and have excel tell me how much was used in a 24hr. period. I need it to show positive and negative as this tank is topped off periodically and I would like to know how much was added. Being able to differentiate the days when Nitrogen was added would be great.

[#2]

Please attach a sample Excel file with your sample date and your manually entered results.

[#3]

I need this to auto calculate for the entire page as a new entry will be added daily. Thanks

[#4]

@Josephlesane 

In the attached file, the formula in C2, copied down rows, is: 

=IF(AND(ISNUMBER($B1),$B2>$B1),
$B2-$B1,
0)

Conversely, the formula in D2, copied down rows, is: 

=IF(AND(ISNUMBER($B1),$B2<$B1),
$B1-$B2,
0)