Thanks everyone.
By report binder I mean the old school ones where you put like the repot inside a folded plastic cover, and then slide the heavier plastic this over where the bind is, and there ya have it. I didn't use the whole slip thing, I just cut off about 2 inches, 4 times, and aquarium sealed them into place. This way my hood still closes properly, and it doesn't look half bad. It took me about 10 attempts to get it right. I first started out with plexi-glass, but either I trimmed them wrong or something, because there were gaps at the top (the female was the first I put in the tank) and the female betta could swim from one side of the tank to the other (not what I wanted to happen 8O ). But this works great.
We'll have to see if this gets algea on it or not, but so far so good. The holes are still big enough that the betta's can see each other, but I have the males on the outside and the females in the middle, so I think it's all just a bunch of harmless flirting...lol
Good luck to anyone if you decide to take this adventure...you won't be disappointed.
Again, thanks for looking.