Just a recap of the age limit for dolphin 6.1.6.

First log in to the admin panel
Then select Advanced Setting
Then scroll down a bit until you see Lowest age possible for site members
change the value to say 13
then scroll down and click on the first save button.
Then click on builders
then click on Field Builders
then click on DateOfBirth under Active Items
then click on Advanced
then set the Minimum value: to 13
then click save
then drag the DateOfBirth block above LookFor block see more then drag it back under LookingFor block. This helps reload the Data Base info sometimes.

Well that should be it. Your new Min Age Limit should now be 13 years on age on the join form.

If the Min Age is still not working for you, you can check two places to see if the values have changed.

The first is in the inc folder. ( inc/params.inc.php )
around lines 45 and 46 you should see the min and max values for age.

$search_start_age = 13;
$search_end_age = 75;

If your start age is still 18 in here just change it to 13 or the same values you put in the admin panel. One reason why the value might not have changed for you is you do not have the proper write permissions on this file !

The second place you can look for this value is in the database. Look in the table ProfileFields then look for the field DateOfBirth.

Well i hope that helps to shed some light on the min and max age for some people having trouble geting the values to work for them.