I have been growing orchids under lights for 3 years and am now going to make the big move and buy a green house. I grow compact Catts,Oncidums and Phals. My greenhouse will have an east west orientation. How best will it be to use 80% and 90% shade cloth for the plants. Should i place the 80% cloth at front for the Catts and Oncidium and the 90% at the qback for the Phals. Your comments will be greatly appreciated.