diff --git a/caimira/apps/calculator/defaults.py b/caimira/apps/calculator/defaults.py
index 339a2bed..82f1cf4a 100644
--- a/caimira/apps/calculator/defaults.py
+++ b/caimira/apps/calculator/defaults.py
@@ -104,8 +104,8 @@ VACCINE_BOOSTER_TYPE = ['AZD1222_(AstraZeneca)', 'Ad26.COV2.S_(Janssen)', 'BNT16
 VACCINE_TYPE = ['Ad26.COV2.S_(Janssen)', 'Any_mRNA_-_heterologous', 'AZD1222_(AstraZeneca)', 'AZD1222_(AstraZeneca)_and_any_mRNA_-_heterologous', 'AZD1222_(AstraZeneca)_and_BNT162b2_(Pfizer)',
                 'BBIBP-CorV_(Beijing_CNBG)', 'BNT162b2_(Pfizer)', 'BNT162b2_(Pfizer)_and_mRNA-1273_(Moderna)', 'CoronaVac_(Sinovac)', 'CoronaVac_(Sinovac)_and_AZD1222_(AstraZeneca)', 'Covishield',
                 'mRNA-1273_(Moderna)', 'Sputnik_V_(Gamaleya)', 'CoronaVac_(Sinovac)_and_BNT162b2_(Pfizer)']
-VENTILATION_TYPES = {'natural_ventilation',
-                     'mechanical_ventilation', 'no_ventilation'}
+VENTILATION_TYPES = {'natural_ventilation', 'mechanical_ventilation', 
+                     'no_ventilation', 'from_fitting'}
 VIRUS_TYPES: typing.List[str] = list(config.virus_distributions)
 VOLUME_TYPES = {'room_volume_explicit', 'room_volume_from_dimensions'}
 WINDOWS_OPENING_REGIMES = {'windows_open_permanently',
diff --git a/caimira/apps/templates/base/calculator.form.html.j2 b/caimira/apps/templates/base/calculator.form.html.j2
index a2179502..788a06d2 100644
--- a/caimira/apps/templates/base/calculator.form.html.j2
+++ b/caimira/apps/templates/base/calculator.form.html.j2
@@ -339,7 +339,8 @@
               
               <div id="DIVCO2_fitting_to_submit" style="display: none">
                 <img id="CO2_data_plot"/><br>
-                <p id="suggestion_lines_txt" class="text-danger mb-3 text-center">The dashed lines are suggestions for the ventilation transition times (Pelt algorithm).</p>
+                <p id="suggestion_lines_txt" class="text-danger text-center">The dashed lines are suggestions for the ventilation transition times</p>
+                <p id="suggestion_lines_txt" class="text-danger mb-3 text-center">(generated from the input data using the Pelt algorithm).</p>
                 <strong>Ventilation scheme:</strong>
                 <div>
                   <input class="ml-2" type="radio" id="fitting_natural_ventilation" name="fitting_ventilation_type" value='fitting_natural_ventilation' checked="checked" data-enables="#DIVfitting_natural_ventilation" form="not-submitted" >
@@ -349,7 +350,10 @@
                 </div>
 
                 <div id="DIVfitting_natural_ventilation" class="form-group mb-0" style="display: none">
-                  <label for="fitting_ventilation_states">Please enter the ventilation state change times, separated by comma - e.g. [8.5, 10, 11.5, 17] </label>
+                  <label for="fitting_ventilation_states">Please enter the ventilation state change times, separated by comma - e.g. [8.5, 10, 11.5, 17]. </label>
+                  <div data-tooltip="Default values indicated below correspond to the dashed lines in the above plot - these are only suggestions and can be changed.">
+                      <span class="tooltip_text">?</span>
+                  </div>
                   <input type="text" class="form-control" id="fitting_ventilation_states" name="fitting_ventilation_states" placeholder="e.g. [8.5, 10, 11.5, 17]" form="not-submitted"><br>
                 </div>
               </div>