Filtering data before validation and database update

My goal is to strip spaces from several fields in my model before validation and database update. I have tried to use setFilters in the validation method in the model without luck. What is the correct way to accomplish this?

Example: " 86 786 99 " will become "8678699"

Added to services.php:

$di->setShared('filter', function() {
    $filter = new \Phalcon\Filter();
    $filter->add('stripspaces', new \KitCloud\Module\Core\Filter\StripSpaces());
    return $filter;
});

StripSpaces.php:

namespace KitCloud\Module\Core\Filter;

class StripSpaces
{
    public function filter($value)
    {
        return preg_replace('/\s+/', '', $value);
    }
}

Entity validation function:

    public function validation()
    {
        $validator = new Validation();

        $validator->add(
            'phone',
            new Regex(array(
                'pattern' => '/^([0-9]{8})?$/',
                'message' => sprintf(_('%s is not valid'), _('Phone number')).' ('.sprintf(_('%d digits'), '8').')'
            ))
        );

        $validator->setFilters('phone', 'stripspaces');

        return $this->validate($validator);
    }