Trying to Style Item in Menu

I am using edu knows and bbPress. I have the navigation info in the header file of my child theme instead of in the navigation.php. This code has worked to get the forum in the menu:

<ul id="nav">
<li class="<?php if (is_home() || is_single()) { ?>home<?php } else { ?>page_item<?php } ?>"><a href="<?php echo site_url(); ?>" title="<?php _e('Home','edu-knows'); ?>"><?php _e('Home','edu-knows'); ?></a></li>
<li class="<?php if (is_page('Forums')) { ?>current_page_item<?php } else { ?>page_item<?php } ?>"><a href="http://uniimi.com/support/forums/" title="<?php _e('Forums','edu-knows'); ?>"><?php _e('Forums','edu-knows'); ?></a></li>
<?php wp_list_pages('title_li=&depth=0'); ?>
</ul>

But when on the Forum page, the css for current_page does not get used. The word Forum should have a green background but it doesn't.

In the live chat S H Mohanjith suggested I try this:

<div id="site-nv">
<?php do_action( 'bp_nav_items' ); ?>
<ul id="nav">
<li class="<?php if (is_home() || is_single()) { ?>home<?php } else { ?>page_item<?php } ?>"><a href="<?php echo site_url(); ?>" title="<?php _e('Home','edu-knows'); ?>"><?php _e('Home','edu-knows'); ?></a></li>
<li class="<?php if (is_page('Forums')) { ?>current_page_item<?php } else { ?>page_item<?php } ?>"><a href="http://uniimi.com/support/forums/" title="<?php _e('Forums','edu-knows'); ?>"><?php _e('Forums','edu-knows'); ?></a></li>
<?php wp_list_pages('title_li=&depth=0'); ?>
</ul>
</div>

It's just not working.