Originally Posted by shellieca
What do you mean by secure? Keep it from falling off or keeping fish in? I 3 tanks with tops, my 2 10g tanks are missing a strip about an 1-1/2 wide all the way across the back & my 46g has about 6-8 inches of open space. Personally I leave them open & there's no need to"secure" the hood.
If you have ever lost a flasher wrasse to carpet surfing, you might feel differently.
On my 37, I used light diffuser grating cut to shape. On my 75, I have glass covers with a semi-clear plastic strip cut to shape. A lot of folks use a window screen net with a clear plastic mesh. The mesh is available from Bulk Reef Supply. You can pretty much only make rectangles with this though. Many use an enclosed canopy to contain the critters.