+1 Wet and Forget concentrate-JonFund wrote: ↑Thu Mar 16, 2023 10:30 am For smaller areas such as patios, I use Wet & Forget. Buy the concentrate and put it in a portable sprayer and I apply it twice a year and I never have any mold or mildew problems. It's completely harmless to plants and grass too. It's particularly good if you have stone pavers, as power-washers can tear up the grout between the pavers.
Use W&F in a pump sprayer that I marked to always get the correct ratio.
Also use W&F on north-facing vinyl siding with good results.