[Myka]

Hmmm...well why would you want to do that to your tank? Kinda wrecks the look I would think. I don't think they'd get over a full divider.

I don't think you'll have any troubles with ammonia or nitrite by scraping the sponges. Many of them will still live, and just slowly die off. If you're worried, just scrape one pane per week.

I just noticed your comment about those eggs in the picture. They are likely snail eggs of some sort, not from the sponges.