Frame for birds netting top?

Recently iv been working on building a cover for my new tank, at first I was planning on just cutting some eggcrate to the shape but after seeing a few threads on the birds netting tops I decided to go that route. My question is what should I use to make a frame out of for it? I thought it would be really easy to just find some small plastic rods I could use to thread through it but after searching high and low at home depot and lowes I can't find anything I'm looking for. So if you have one, what did you use for the frame? Should I stay away from metal and wood just in case it may leach something into the water? cause im sure I'll get it wet all the time.

And also I have a 150w mh over the tank, think it will Melt the birds netting? Didn't think of that when I bought it ><.

Thank you for any feed back.

 

Get the screen door/window framing from Home Depot or Lowes.

Screen Window Frame

Jack