# How do I mark a condition entry as not tested?

Maquarium allows you to enter a condition value that is not tested or n/t. You may want to do this when you enter measurements of some, but not all, chemicals you have selected in the condition list. When graphing condition entries, not tested values will be extrapolated with surrounding measured values. To enter a value as n/t, do the following:

Double-click the condition entry you want to edit in the Conditions list.

Select all the text in the field.

Press the Delete key to remove the text.

Press the Tab or Return key to advance to the next field.

The entry will then show "n/t" or not tested. To edit this value, simply double-click the field and entry the measured condition value as you would normally.