Wordpress Second query unlimited posts

    <div id="main-content-werk">
        <div id="slider">

          <?php $do_not_duplicate = array();
          $slider = new WP_Query('category_name=werk&posts_per_page=5');
           while ($slider->have_posts()) : $slider->the_post();
           $do_not_duplicate[] = $post->ID;?>
           <a href="<?php the_permalink() ?>" title="<?php the_title(); ?>"><img src="<?php echo get_post_meta($post->ID, 'slider-image', true); ?>" alt="" title="<?php the_title(); ?>" /></a>
           <?php endwhile; ?>
         </div> <!-- END slider -->

         <br clear="all" />

        <?php $args = array(
        'category_name' => 'werk',
        'post__not_in' => $do_not_duplicate,
        'paged' => get_query_var('paged')
        ); ?>

        <?php $belowslider = new WP_Query( 'category_name=werk&posts_per_page=-1&offset=5' ); ?>

        <div id="smalls-wrapper" style="width:900px; margin:0 0 0 5px;">

          <?php while ($belowslider->have_posts()) : $belowslider->the_post(); ?>

          <div id="smalls">
            <div id="smalls-thumbnail"><a href="<?php the_permalink() ?>"><?php the_post_thumbnail('thumbnail'); ?></a></div>
            <div id="smalls-title"><a href="<?php the_permalink() ?>" title="<?php the_title(); ?>"><?php the_title(); ?></a></div>
            <div id="smalls-excerpt"><?php echo excerpt(10); ?></div>
          </div> <!-- end smalls -->

          <?php endwhile; wp_reset_query(); ?>

        </div> <!-- end smalls-wrapper -->