Algae Removal and Acid Washing for Bennington Pontoons | Technical Cleaning That Won’t Damage Your Investment
You pull your Bennington out of the water after a long summer, and there it is—a thick green stripe along the waterline that looks like it’s becoming part of the aluminum.
Here’s the thing about owning a Bennington pontoon boat. That green slime isn’t just ugly. It’s algae, and if you leave it there, it starts eating into the protective layer on your pontoons. Scrub too hard with the wrong method, and you’ll scratch the metal. Use the wrong acid, and you’ll etch it permanently. But clean it right, and those tubes will look better than they did the day you launched. Let me walk you through the exact protocols that Bennington owners use to get that mirror finish back.
TL;DR
Algae removal requires a gentle touch first—soft brush, mild soap, and elbow grease. For stubborn growth, acid washing (using products like Oxisolv or diluted muriatic acid) dissolves mineral deposits and algae roots without scrubbing. Never use full-strength muriatic acid, never let acid dry on the tubes, and always neutralize with baking soda solution afterward. The three-towel method (clean, acid, neutralize) saves hours of scrubbing. Sharkhide protectant after cleaning seals the metal and prevents future growth.
Key Takeaways
- Start with the gentlest method possible—soap and water before acid.
- Algae loves stagnant water—boats that sit in slips grow more than boats used daily.
- Acid washing removes growth without scrubbing, which prevents scratching the aluminum.
- Always dilute muriatic acid (10:1 water to acid) and add acid to water, never water to acid.
- Neutralization is mandatory—baking soda and water stops the acid from eating your tubes.
- Sharkhide after cleaning seals the metal and makes future cleaning easier.
Why Algae Is Worse Than You Think
Most boat owners think algae is just a cosmetic problem. It’s not. Algae attaches to aluminum and holds moisture against the metal. That moisture, combined with minerals in the water, creates a perfect environment for corrosion.
Have you ever noticed that the green stripe is always exactly at the waterline? That’s where oxygen, water, and algae meet—the corrosion trifecta.
On a Bennington pontoon boat, the pontoons are made from marine-grade aluminum. It’s tough, but it’s not invincible. The protective oxide layer that naturally forms on aluminum can be compromised by long-term algae contact. Once that happens, you get pitting—tiny holes that collect more algae and lead to deeper corrosion .
Rhetorical question: Would you let mold grow on your house siding for a year? Then why let algae sit on your $10,000 pontoons?
The Non-Acid Approach: When You Don’t Need Chemicals
Before you break out the heavy stuff, try this. You might be surprised how much comes off with just soap and water.
What You’ll Need
- Soft-bristled brush (nylon, never steel)
- Mild dish soap (Dawn works great)
- Bucket of warm water
- Hose with spray nozzle
The Process
- Wet the pontoons thoroughly
- Mix soap and water in the bucket
- Scrub in circles, focusing on the algae stripe
- Rinse immediately—don’t let soap dry on the metal
- Repeat as needed
Pro tip: A pressure washer on low setting (under 1,500 PSI) can help, but keep the tip at least 12 inches away from the aluminum. Too close and you’ll etch the metal.
One owner shared: “I tried everything on my toons. Simple Green, pressure washer, scrubbing. Nothing touched that black algae line except acid” . Sometimes you need the big guns.
“The white oxidation and black scum line won’t come off without acid. Don’t waste your time scrubbing for hours—use the right chemical and let it do the work.” — Club Bennington forum member
Rhetorical question: Have you ever scrubbed so hard your arms gave out, only to look at the boat and see the algae still there? That’s when you know it’s time for acid.
Acid Washing: The Technical Protocol
Acid washing sounds scary, but it’s a standard marine procedure when done correctly. The acid dissolves the mineral deposits that algae roots attach to. The algae slides right off with a gentle rinse.
Choosing Your Acid
Oxisolv (Bennington-recommended) – This is a biodegradable, non-fuming aluminum brightener. It’s safer than muriatic acid and specifically formulated for pontoons . It costs more, but many owners say it’s worth it.
Muriatic acid (pool acid) – This is the strong stuff. It works fast and cheap, but it’s dangerous if mishandled. Always dilute it (10 parts water to 1 part acid). One owner warns: “Muriatic acid will absolutely dull your toons if you leave it on too long” .
The toon cleaner “recipe” – Some owners mix their own: 1 gallon of water, 1 quart of muriatic acid, and a squirt of Dawn dish soap. The soap helps the acid spread evenly .
Pro tip: If you use the homemade recipe, write the ratio on the bottle. You’ll forget by next season. Ask me how I know.
Safety Equipment (Non-Negotiable)
- Chemical-resistant gloves (not just latex—get nitrile or rubber)
- Safety goggles (not just glasses—full seal)
- Long sleeves and pants (acid splashes burn)
- Closed-toe shoes (preferably rubber boots)
- Respirator if working in an enclosed space (outside is better)
Safety reminder: Always wear life jackets and follow local boating laws when operating any vessel. For acid washing, add another rule: always have fresh water running nearby to rinse skin immediately if splashed.
Timeline: Pontoon Cleaning Technology Evolution
Pre-2000s – Wire brushes and harsh abrasives. Effective but destroyed the protective oxide layer.
Early 2000s – Muriatic acid becomes common. Cheap and effective, but dangerous and easy to mess up.
2010s – Specialized marine aluminum cleaners like Oxisolv hit the market. Safer but more expensive.
2020–present – Two-step systems (cleaner + neutralizer) become standard. Sharkhide protectant gains popularity for post-cleaning sealing.
Modern Bennington boats – Owners combine gentle annual cleaning with protectant application, reducing the need for heavy acid washes.
The Step-by-Step Acid Wash Protocol
This is the method that experienced Bennington owners swear by. Follow it exactly.
Step 1: Preparation
Move the boat to a well-ventilated area, preferably away from other vehicles and plants. Cover anything you don’t want acid on—the trailer tires, the concrete driveway, your neighbor’s cat. Have your neutralizer ready (baking soda and water in a spray bottle).
Step 2: Wet the Pontoons
Use a hose to thoroughly wet the aluminum. This prevents the acid from drying too fast and gives you a little dilution buffer.
Step 3: Apply the Acid
Working from bottom to top (to prevent drips on untreated areas), spray or wipe on your diluted acid solution. One section at a time—don’t try to do the whole boat at once.
Pro tip: A garden sprayer (the kind for weed killer) works perfectly for applying acid. Just label it clearly so nobody accidentally uses it for Roundup later.
Step 4: Let It Work
Give the acid 2-5 minutes to do its job. You’ll see the algae start to change color and lift. Do not let it dry. If it starts drying, rinse and reapply.
Step 5: Scrub Gently
A soft brush might help, but usually the acid does all the work. One owner said: “After about two minutes, I hit it with the pressure washer and it came right off” .
Step 6: Rinse Thoroughly
Use a hose or pressure washer (low pressure) to rinse the acid off completely.
Step 7: Neutralize
Mix a solution of baking soda and water (about 1 cup baking soda per gallon of water). Spray or wipe this over the areas you just cleaned. It will fizz slightly—that’s the acid neutralizing. Rinse again.
Skipping neutralization is the #1 mistake. Residual acid continues eating the aluminum for weeks, leaving a dull, etched finish.
Rhetorical question: Would you put acid on your skin and then just wipe it off? No. You’d neutralize it. Your pontoons deserve the same care.
The Three-Towel Method: A Pro Technique
Here’s a method shared by a detailer that saves hours of work. You’ll need three towels and three spray bottles.
Towel 1 (Clean) – Soap and water. Removes loose dirt and algae.
Towel 2 (Acid) – Diluted acid solution. Breaks down the stuck-on growth.
Towel 3 (Neutralize) – Baking soda and water. Stops the acid reaction.
Work in 2-foot sections. Clean, then acid, then neutralize. Move to the next section. No waiting, no drying, no re-scrubbing.
One owner who tried this said: “I did the whole boat in 45 minutes. Normally that would take me all weekend” .
Pro tip: Use different colored towels so you don’t mix them up. Blue for clean, red for acid, yellow for neutralize. Your future self will thank you.
What Not to Do: Common Mistakes
I’ve seen these mistakes destroy pontoons. Learn from others’ pain.
Don’t use full-strength muriatic acid. One owner tried this and said: “It turned my shiny toons into a dull mess. It pitted the aluminum and I had to spend hours polishing” .
Don’t let acid dry on the tubes. Once it dries, it concentrates and etches. Work in small sections and keep the tubes wet.
Don’t use steel wool or wire brushes. These scratch the aluminum and leave tiny steel particles that rust and cause more corrosion.
Don’t acid wash in direct sunlight. The acid dries too fast. Do it on a cloudy day or in the shade.
Don’t forget to protect your trailer. Acid drips eat through trailer paint and can weaken welds over time. Rinse your trailer immediately after finishing the boat.
Rhetorical question: Have you ever rushed a job and made things worse? Take your time with acid. Slow is smooth, and smooth is safe.
Cleaning Method Effectiveness vs. Risk
This chart shows the trade-off between how well each method cleans and how likely it is to damage your pontoons.
See how full-strength acid sits in the high-risk zone? That’s where pontoons go to die. Stay in the mild-to-moderate zone for safe cleaning.
After the Clean: Protecting Your Work
You just spent hours making your pontoons beautiful. Don’t let them go back to green next month.
Sharkhide protectant is the gold standard. It’s a clear coating that seals the aluminum and prevents oxidation and algae attachment. One application lasts 2-3 years .
Application is simple: wipe it on with a soft cloth, let it dry for 30 minutes, then buff. Don’t get it on your Premium Marine Vinyl Seating—it’s hard to remove.
Pro tip: Apply Sharkhide when the aluminum is clean and dry. Not right after acid washing. Give it at least 24 hours to fully dry out.
One owner who used Sharkhide said: “Two years later and the pontoons still look great. Algae washes off with just soap and water now” .
Rhetorical question: Would you wax your car and then never wash it again? No. But Sharkhide makes each wash ten times easier.
Seasonal Maintenance Schedule
After every trip:
- Rinse pontoons with fresh water (especially if boating in salt or brackish water)
- Wipe down waterline areas with a soft cloth
Monthly:
- Inspect for algae buildup
- Light scrub with soap and water if needed
- Check for any white oxidation (early sign of corrosion)
Annually (spring or fall):
- Full inspection of pontoons and welds
- Acid wash if algae or oxidation is present
- Apply Sharkhide protectant
Every 3-5 years:
- Professional polishing if desired (mirror finish)
- Weld inspection by a marine mechanic
Comparison Table: Pontoon Cleaning Products
| Product Type | Best For | Application Difficulty | Key Feature | Price Range |
|---|---|---|---|---|
| Oxisolv Aluminum Cleaner | Safe, effective acid wash | Easy (spray on) | Biodegradable, no fumes | $25 – $45 |
| Muriatic Acid (diluted) | Heavy algae and mineral deposits | Medium (requires mixing) | Cheap and powerful | $10 – $20 |
| Sharkhide Protectant | Post-cleaning sealing | Easy (wipe on) | Lasts 2-3 years | $60 – $100 |
| ToonBrite | One-step cleaning | Easy | Contains acid + brightener | $30 – $50 |
| Soft-bristle brush kit | Daily and weekly cleaning | Easy | Won’t scratch aluminum | $15 – $30 |
FAQ: Your Algae and Acid Washing Questions Answered
What makes Bennington boats unique for cleaning?
The Reinforced Aluminum Construction uses high-quality marine-grade aluminum that responds well to acid washing, but the Heavy-Duty Crossmembers can trap debris if not rinsed thoroughly .
Are Bennington pontoons good for DIY acid washing?
Yes, but follow safety protocols carefully. The Elliptical Sport Package (ESP) tubes are larger and require more product, but the process is the same.
How fast can a Bennington pontoon go after acid washing?
The same as before. Acid washing removes growth that creates drag, so you might actually gain 1-2 mph at wide open throttle.
What acid strength is best for a Bennington boat?
Diluted muriatic acid at 10:1 water-to-acid, or a marine-specific product like Oxisolv. Never use full-strength acid on pontoons .
Are Bennington boats safe to acid wash on the trailer?
Yes, but rinse the trailer thoroughly afterward. Acid drips can damage trailer paint and welds over time.
What maintenance prevents algae buildup between washes?
Sharkhide protectant reduces attachment. Also, boats that are used regularly have less algae than boats that sit still. Movement disrupts growth.
Can you use a Bennington boat for watersports after acid washing?
Absolutely. Just wait 24 hours after applying Sharkhide for it to fully cure before getting the boat wet.
The Bottom Line on Pontoon Cleaning
Here’s what experienced Bennington owners know. Algae happens. It’s not a sign you’re a bad boat owner—it’s just part of boating. But how you handle it makes all the difference. Start gentle. Escalate to acid only when needed. Always neutralize. And for the love of your pontoons, seal them with Sharkhide when you’re done.
Your Bennington pontoon boat is an investment. The pontoons are the foundation of everything. Treat them right, and they’ll hold their shine—and their value—for decades.
What’s your favorite Bennington boat feature or on-the-water experience? Share your thoughts in the comments below.
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