30 SECONDS Outdoor Cleaner Dirt,Mold & Mildew Cleaner & Stain Remover Concentrate | 1 Gallon

Why it's worth it

30 SECONDS mixes one-to-one with water, so a gallon of concentrate becomes two gallons of solution. Green algae and mildew staining start dissolving within a minute of contact, which makes it the pick when the house needs to look good by Saturday.

It's genuinely fast, and that changes how you work. Applied at full 1:1 strength to green-stained vinyl, staining visibly breaks down in well under a minute. You spray a section, watch it lift, and move on. Compare that with a maintenance product where you spray and come back in two weeks.

The dilution is impossible to get wrong. One part concentrate, one part water. No ounces-per-gallon math, no label squinting. A gallon of concentrate becomes two ready-to-use gallons, which is a lot of wall for a single container.

From our review of 7 siding cleaners, by David Sinclair, Managing Editor

What we like

• +It's genuinely fast, and that changes how you work
• +The dilution is impossible to get wrong
• +The surface list is unusually broad
• +It's the right first pass on a neglected house

What to know

• –Bleach chemistry means plant precautions
• –It's more prep than a hose-end bottle
• –It won't touch chalky oxidation