If you've walked on your dock after a rain and nearly slipped, you already understand why algae is more than an eyesore. In Jacksonville's warm, humid climate, algae and marine growth build up faster than anywhere else in the country. Left untreated, it creates genuine safety hazards and accelerates wood decay underneath the surface.
Why Algae Grows So Fast Here
Northeast Florida checks every box for aggressive algae growth: water temperatures that stay warm most of the year, high humidity, abundant sunlight, and nutrient-rich tidal water. Any dock with shade from a boat, a canopy, or overhanging trees will show visible algae within weeks of cleaning without treatment. On exposed docks in full sun, growth is somewhat slower — but still relentless.
The Problem with Pressure Washing Alone
High-pressure washing blasts the surface clean but leaves spores behind — and on wood, aggressive pressure washing strips away the wood fiber that protects against future moisture penetration. It looks clean for a few weeks and then grows back faster than before.
Professional dock cleaning uses a soft-wash approach: lower pressure combined with a biodegradable algaecide that kills the growth at the root, not just at the surface. The result lasts significantly longer and is safer for the wood structure and the surrounding water.
Wood Treatment After Cleaning
Cleaning without treating is a missed opportunity. After a proper soft wash, wood is open and receptive to UV and moisture protection. Applying a penetrating wood treatment immediately after cleaning seals the wood, slows future algae regrowth, and extends the time between service visits significantly. For pressure-treated pine docks (the most common in Jacksonville), we recommend treatment every 1-2 years depending on sun exposure and shade.
Safety First
Beyond longevity, a clean dock is a safe dock. Wet algae on wood or composite surfaces creates a slip hazard comparable to black ice. For households with children, elderly family members, or guests who aren't familiar with waterfront surfaces, this is a genuine liability. A dock that's slippery enough to cause a fall into tidal water is a serious risk.
Dock cleaning in Jacksonville starts at $0.75 per square foot. A typical residential dock runs 200-400 square feet, so a full cleaning and treatment is $300-600 — money well spent for safety and structural longevity.