From a previous post of mine...
I'm not sure if this has been officially been brought up here, but for those that seek better alternatives to that of egg crate (light diffuser) yet preventing your livestock from jumping from their aquarium, I thought I would share the following information brought up in a past ReefCentral thread since many are not aware of its use.
Polypropylene (PP) netting has been used in the agricultural industry for years and is a proven product for its strength, durability, resistance to caustic solutions and other degradations, UV
inhibitors, and is long-lasting.
Most of the PP netting available is black, automatically includes UV
inhibitors, and known to surpass 20yrs; however, the same cannot be said for its clear counterpart. Why is this? Because the majority of clear PP does not contain UV
inhibitors so depending on the application, the product may degrade at a much faster rate. As far as I have found, there is only a single company that provides a UV
inhibiting clear PP:
Welcome to Industrial Netting - Netting, Mesh and Screens for Industry
Hole Size: 1/2"
They do have just one other clear PP available with UV
inhibitors, but it is much thicker and not easier to work with IMO
/IME. I've been told this particular netting will last at the very least, 5+yrs without degrading. As far as actual application, many have used aluminum frames (window framing), but this technique has also been questioned in eventual aluminum leaching. IMO
a thin acrylic frame would be best applied and completely inert. Here is the RC thread just to show you the actual netting (I do not know which netting product # they purchased):