The reason for the light was to brighten it up it was a 600 watt hps for flowering i had to use a white tarp which did let the sunlight in but put the 600 watt hps to help brighten it up and it did the job it did put off some heat but it was outside so the propane heaters kept it nice and warm .During the summer june july august good weather here the garden was uncovered i had to build the shelter at the end of september. And as far as mold it is a big problem here in wa for outdoor plants and can appear overnight so you just have to cut it off . There are certain strains that are mold resistant but i have yet to find one.Also in the pics the plants were about two weeks from being done and they got way bigger at the end harvest time.