(Image credit unknown, found when shared on Facebook.)

Experienced pontooners will no doubt be familiar with the troublesome algae that can build up on the pontoons over time, and the longer you leave it, the far worse it will get. So, what’s the solution and how can you clean the algae off your pontoon boat?

So firstly, if you leave it on there after your trip it’s going to be a lot harder in the future to remove it.

That’s why I always recommend that as soon as your boat leaves the water you wash the pontoons. Doing this will save you so much time in the future.

But even if it has built up over time, there’s still a method that I recommend that will help you clean algae off your pontoons in under 20 minutes, which I will come onto in a moment.

But let’s just re-iterate one thing before I get into that.

If you want to keep your pontoon in top notch condition and want to reduce the cleaning work you will have in the future, clean the pontoons as soon as you exit the water. I can’t re-iterate this enough.

The best way to do this, would be use a pressure washer, and if needed, some of those green Scotch Brite pads (see on Amazon). Buy some and keep them on your pontoon boat!

pressure washer

Sun Joe Pressure Washer

The pressure washer that I use is the Sun Joe SPX3000. It’s got 2,030 Psi which is a massive amount of pressure, and really does mete out punishment to algae – I wouldn’t be without mine, and you can pick one up on Amazon relatively cheaply.

Something else you might want to consider: I’ve even had my passengers get out and swim around the boat whilst in the water with cleaning pads to do some light scrubbing! Always on the promise of a beer once they get back into the boat of course!

So, for one last time: don’t let it sit and dry and then scrape it off later, as it will be so much harder – it will stick on like crazy and is really tough to shift. You can clean it off in under 20 minutes though with a little hack I will show you in a moment.

How to Get Clean Off Stubborn Long-Term Algae

But what if you have left it and haven’t cleaned it off immediately?

Algae can be pretty tenacious when it attaches to aluminum. It comes off to a certain degree using a pressure washer and brush but getting the pontoons perfectly clean is more difficult.

This doesn’t just apply to cleaning algae off a pontoon boat, but also things such as barnacles, quagga mussels, zebra mussels, and other marine scum and debris.

Just pressure washing one inch at a time or sanding works, but it is very hard work and can take a long time – which is why I always advise you clean as soon as you are out of the water.

You need to be careful when working with aluminum. Boat bottom cleaners designed for fiberglass should never be used, as it will damage the pontoons. You don’t want to permanently stain, streak, or discolor your boat – or in worse cases puncture the pontoon.

It’s essential to use the right products and techniques to get the best results when knowing how to clean algae off your pontoons.

The product I recommend is use for really bad algae on your pontoon is Algex. You can buy Algex spray on Amazon – see it here (ignore the reviews you see on Amazon, it’s amazing on aluminum pontoons I promise you).

Algae Cleaning

Use Algex and a pressure washer to clean the algae stuck to your pontoon boat.

It was actually invented for marine cleaning to clean algae, barnacles, zebra mussels, quagga mussels and more from aluminum boats and works amazingly well.

It works very aggressively to remove marine growth and scale, but not that aggressive that it will damage your aluminum pontoons.

All you do is spray it over the algae, wait for two minutes, then start spraying with a pressure washer. In most cases the algae will clean off very easily leaving you with almost new looking pontoons.

If you don’t have a pressure washer, try cleaning using a normal garden hose at the highest setting. It won’t be as good at cleaning algae off, but could work if you don’t have a pressure washer.

How to Stop Algae Sticking to Your Pontoons

Once you’re done, you can polish the pontoons with VS721 bottom coat (buy on Amazon) as this will help reduce algae attaching in the future.

I also recommend that you apply a protective coating of a product Alumetron before you use the VS721. What this will do is fill in the grains of the aluminum and make it a lot smoother – algae finds it harder to stick to smoother surfaces.

You might have also heard of a product called Shark Hide aluminum sealer (buy on Amazon). Many pontooners mistakenly believe this will stop algae sticking to their pontoon boat so they don’t have to clean it after exiting the water.

This isn’t the case, as Sharkhide won’t help stop it, but it does makes it a lot easier to remove in the future so is worth buying just for that benefit alone.

There is a more detailed explainer on anti-fouling paint vs VS721 and how you can stop algae from sticking to your pontoons. Read that by clicking here.

I have also put together an extensive guide on how to polish your pontoon tubes for the best mirror-like results; it takes just 5 simple steps.