Best easy top for a 20gal dart frog vivarium

[tylototriton]

I would go with a solid piece of glass or two (two is more manageable I think).
Aquarium lids sometimes have gaps, and even though the gaps probably aren't big enough for the frogs to escape they are definitely big enough for fruit flies to get out!
I've done several different tops for my tanks. I've used plastic wrap under a screen lid. That wasn't classy at all, but it worked just fine (for years)!
I've done two panes of glass. I find having a couple panes makes it a little easier, that way you don't have to lift a whole large piece. I didn't even bother with a hinge, I just sat them onto the lip.
My current favorite is to build a small screen and then use cut glass for the rest. You can see the sort of screens i'm talking about in John's 10g Vert thread. I like them because they do allow some airflow and keep the temperature down (my lights were making the tanks a little warm).

For your tank, I would do one or two pieces of glass. It'll be cheaper than buying a glass aquarium lid. NE Herp has great handles that just stick right on.

Cheers,
Alex

[MillerFroggies]

Thanks everyone I am going to try and find a place to get a custom top cut. Until i can get one I am going to use an old glass fish tank top to let the plants grow in for a few months before I put any frogs in and to make sure I can get everything right before i get the little guys.