^ Done.

I am a bit concerned about the way I've set the database users up though and wonder if I have bothced that in some way. I tried to set up rotating database users but maybe didn't get it right.

For both installs I have...

$dbuser[] = 'zncif2yUBqK';
$db_pwd[] = '***';

$dbuser[] = 'user_2';
$db_pwd[] = '***';

$dbuser[] = 'user_3';
$db_pwd[] = '***';

$dbuser[] = 'user_4';
$db_pwd[] = '***';

...in includes/configure.php

define('DB_SERVER_USERNAME', 'zncif2yUBqK');
define('DB_SERVER_PASSWORD', '***');

...in admin/includes/configure.php

The passwords for the extra users I added have some special characters so maybe that is causing problems. I'm pretty sure I created the databases OK though.