List sub pages with custom field content converting image ID to URL

I ended up with this

                    <?php
                    //get children of page 241 and display with custom fields

                    $args=array(
                      'post_parent' => 825,
                      'post_type' => 'page',
                    );
                    $my_query = null;
                    $my_query = new WP_Query($args);
                    if( $my_query->have_posts() ) {

                      while ($my_query->have_posts()) : $my_query->the_post(); ?>
                            <?php $img = wp_get_attachment_image_src( get_post_meta($post->ID, 'product_logo', true)); ?>
                            <?php $alt_text_for_logo = get_post_meta($post->ID, 'alt_text_for_logo', true); ?>
                            <div class="column small-6 medium-4 product">
                                <a href="https://wordpress.stackexchange.com/questions/227569/<?php the_permalink() ?>" title="<?php the_title_attribute(); ?>">
                                    <span> <img src="<?php echo $img[0]; ?>" alt="<?php echo $alt_text_for_logo; ?>" /></span>
                                    <h2><?php the_title(); ?></h2>
                                </a>
                            </div>
                       <?php endwhile; } ?>
                    <?php wp_reset_query();  // Restore global post data stomped by the_post().?>
            </div>