I am looking to ad shade cloth to my full sun southern exposure lanai in z10. the lanai has a screen which is 20% and wondering if I should add the 40% or 50%. I will be doing the "aluminet" pre hemmed product.

will be growing mainly neo's. solids colors not many variegated .

I do not want to buy a product then wish I would have bought another one. the lanai is large so it will take allot of material