AlgaeRemoval
Black Streaks Erased

Both, slowly — the colonies hold moisture and consume filler minerals. Ugly arrives years before damage, which is why treatment now is cheap insurance.

Algae favors slopes with less direct sun and slower drying — typically north-facing and tree-shaded runs. The streak-free south slope is getting free UV treatment daily.

Homebrew mixes at wrong strengths kill lawns, corrode gutters and streak siding — and ladders plus wet roofs end badly. Soft washing exists because the chemistry and the safety both matter.

Gloeocapsa magma algae feeding on the limestone filler in shingles — an organism, not dirt, which is why washing never fixes it.

Copper-infused granule lines carry long stain warranties and genuinely resist recolonization — the permanent fix if a replacement is in your future anyway.

Correct soft-wash dilutions are shingle-safe; homebrew strengths kill lawns, corrode metal and void warranties. The chemistry ratios are the whole job.

Typically several years before recolonization shows — shaded north slopes recolonize fastest, and ridge metals stretch the interval.

The algae lives outside and isn’t a health hazard indoors — the cost is curb appeal now and slow shingle degradation over years.