Best Patio Cleaner: GK vs SmartSeal, Pro-Kleen, Wet & Forget, Patio Magic, SCRUBB

The UK market is flooded with outdoor cleaners, all promising to be the best patio cleaner and most capable of restoring your patio to its former glory. From fast-acting black spot removers to low-effort "spray and leave" algae removing solutions, the choice can be overwhelming.

While many products deliver a decent clean, understanding the differences in their formulas, price, and long-term effectiveness is key to choosing the best patio cleaner for your situation, and finding a solution that provides a truly superior, lasting result.

Let’s take a look at how some of the most popular cleaners on the market compare to the professional-grade solutions from GK Products.

1. The Fast-Acting Black Spot Remover Battle

When faced with stubborn black spots and lichens, many homeowners and professionals turn to powerful, quick-acting cleaners. Products like SmartSeal Patio Clean Xtreme and Pro-Kleen Ultimate Black Spot Destroyer are popular choices that typically contain sodium hypochlorite and can show dramatic results in a matter of hours. Their strength lies in a rapid, high-impact chemical reaction.

However, GK Products offers a more refined approach with GK Black Spot Remover. While equally powerful, its formula is designed to be thixotropic - a semi-gel like consistency with a unique alkali blend and wetting agents that clings to the surface for effective removal of both organic and non-organic staining.

This unique property allows for an extended dwell time of up to 24 hours, giving the active ingredients a much longer period to penetrate and break down the ingrained lichen without the need for a highly aggressive, instant reaction. This method is non-invasive, providing a superior, deep clean that is kinder to the integrity of the stone.

SmartSeal Patio Cleaner Xtreme

Price - £31.95 (Direct)

5 litre - treats 40m2

70-90% Sodium hypochlorite solution

1-10% Sodium hydroxide

Pro-Kleen Ultimate Black Spot Destroyer

Price - £29.95 (Direct)

5 litre - treats 40m2

9.8% Sodium hydrochlorite

No other information available on active ingredients.

GK Black Spot Remover

Price - £19.99 (Direct)

5 litre - treats 20m2 (heavy soiling) 30m2 (light - medium soiling)

<7% Sodium hydrochlorite solutions

<1% Sodium hydroxide

Contains a unique alkali blend with wetting agents.

2. The Long-Term Green Growth Solutions

For general green growth like algae, mould, and mildew, the "spray and leave" category is a favourite for its low-effort appeal. Brands like Wet & Forget, Patio Magic and SCRUBB have built their reputation on this model. You apply the product, and over weeks or months, the rain and weather naturally wash away the dead growth. The main downside is the time it takes to see results, and the protection typically lasts around 6-12 months, requiring annual reapplication.

GK's solutions in this space, GK Pro and GK Greener Kleener, are engineered with a professional edge. GK Pro uses a pure, high-concentration DDAC (Didecyldimethylammonium chloride) biocide, which is a cleaner and more effective compound than the BAC (Benzylammonium chloride) used in many competing products. This purity ensures predictable performance, even in hard water areas.

Crucially, GK Pro doesn’t just clean - it provides a long-lasting residual action that actively prevents regrowth for at least two years after treatment, meaning your patio can stay pristine for over three years before you need to re-treat.

For those seeking a safe and effective bleach-free option, GK Greener Kleener offers a powerful alternative with a near-neutral pH.

Wet & Forget

Price - £35.89 (Direct)

5 litre - treats 300m2

Benzalkonium chloride

Patio Magic

Price - £20 (Wickes)

5 litre - treats 170m2

Benzalkonium chloride

Isotridecanol, ethoxylated

SCRUBB

Price - £21.99 (Screwfix)

5 litre - No coverage information.

Benzyl-C12-16-alkyldimethyl, EC chlorides

Alcohols; ethoxylated

GK Pro

Price - £84 (Direct)

5 litre - treats 1000 - 1500m2

45 - 50% Didecyldimethylammonium chloride

10 - 15% Ethanol; ethyl alcohol

GK Greener Kleener

Price - £22.79 (Direct)

5 litre - treats 100 - 125m2

<5% Didecyldimethylammonium

<2% Ethanol; ethyl alcohol

3. Price vs. True Value

At first glance, a product with a lower price tag might seem like a better deal, but when it comes to outdoor cleaning, results, coverage and longevity are the real indicators of value.

Some popular cleaners are either ready-to-use (which means poor coverage per bottle) or require low dilution rates.

In contrast, GK's professional-grade products often have very high dilution rates. For example, a single 5-litre tub of GK Pro can be diluted at 50:1, allowing it to treat an immense surface area of over 1,000 square metres.

GK Pro and GK Greener Kleener are also the only DDAC biocides, which means that they provide a more predictable and effective cleaning solution when compared to other products on the market.

When you factor in this superior coverage and the fact that GK Pro’s results can last for years, its cost per square metre and long-term value far outweigh the initial price of many competing products.

GK creates effective formulas with purer ingredients. These provide a deeper cleaning experience with longer-lasting results, and are also better for surfaces such as patios and driveways. This protects them against expensive damage that can occur from harsh chemicals such as acid and bleach.

The Verdict

While there are many effective cleaners on the market, GK Products stands out by offering a professional-grade solution for every major patio cleaning challenge. It's not just about a quicker or easier clean; it’s about a superior, long-lasting clean delivered by high-quality, targeted formulas.

By investing in GK, you're choosing a solution that is more precise, more durable, and more cost-effective in the long run, ensuring your outdoor spaces stay immaculate for years to come.