Recommendation needed for best deck prep and stain products
We live in South Central Pennsylvania and have a 16 x 20 pressure treated deck that was built in August 2016. The deck is located on the north side of the house, in an "L" between the house and an enclosed porch. It gets some sun during the morning hours but is shaded for most of the afternoon. There is always a problem with moss, mold, mildew and algae on the north sides of structures in this part of Pennsylvania.
In June 2018, we thoroughly cleaned and then treated the decking with Thompsons Waterseal Advanced. The product performed ok for a few months but we have had extremely wet conditions in 2018 and early 2019 and we've noticed that the sealant seems to have worn quickly and there is noticeable mold or mildew appearing on much of the decking. We are planning to strip/clean and retreat just as soon as the weather allows.
We assume that we will need to use a stripper first, to remove any remaining Thompsons' product, then apply a brightener, and finally apply a stain in order to correctly restore the decking. We would prefer a clear or natural stain color. Our question is, which product line do you feel would be the best suited for our particular application? We were leaning towards the Defy line because of it's ability to inhibit mold/mildew growth but wondered if the Restore-A-Deck line would work as well. The ability to prep and stain in a single day is plus, especially if the rainy weather continues this spring/summer.
Any recommendations and advice would be greatly appreciated. Thanks!