I am sorry I'm putting this here. I had someone send me a private message today about my divided setup. I read the message, closed the page came back and the message was gone. I hate leaving question unanswered so I figure the person will see it here.
My 10 gallon is divided with a divider made by Penn-Plax. I picked this up a Pet Supplies Plus for just over $10.00. I really like this product. If your using any substrate make sure you bury some of the divider in it. This will make it very stiff. I'm sure all the stores have them. If I remember right you had a 5 gallon. I don't know if they make one for a 5. If they don't here is the link to a home made one.
I hope this helps. If you read this send me a message