I have an only acrylic tank with a welded on OF that I want to remove. I really don't feel like cutting the back wall but I was thinking a multi tool similar to this one Link might work. I'm not conserned with scratches or scrape marks since it's just going to be a sump. If anyone around the Pittsburg area has one that I can borrow for the day (or I can bring it by) let me know, I've never used one so and I'd hate to buy one just for this. Other than using a hack saw blade manually for a couple of hours, cutting the back wall or a multi tool I can't think of anything else so let me know if you have any other ideas.