Sodium Hypochlorite Patio Cleaner – 2 x 5 Litres of Industrial-Strength Algae & Black Spot Remover – Powerful Driveway & Paving Cleaner – Professional Outdoor Cleaning Solution for Concrete

This is my go-to for patio and driveway cleaning. I use it mixed with water and a surfactant in a jerry can, and it performs extremely well with my pressure washing setup. Black spots, algae, and grime come off fast, and you start seeing results in under 10 minutes.Pros:• Very strong SH mix (14–15%) that works quickly• Great value at under £18 for 10L• Ideal for concrete, tiles, and stone• Pairs perfectly with surfactant and water for pre-treatmentCons:• Strong chlorine smell (normal for SH)• Will bleach fabric and sensitive surfaces—use PPEVerdict:Excellent for exterior pressure washing pre-treatments. Results speak for themselves.

This was an absolute game changer for me. My patio was covered in black spot and was looking very tired. I tried this out got 10ltrs. Only need 5 ltrs to complete the clean. I did mix it strong and would advise a face mask as this is powerful stuff. I applied with a sprayer a slab at a time and you could see it start to fizz immediately. I coated the whole patio which is approx 25ft x 16ft and had a bit left in the spacer and I gave a little more to the more heavily stained ones. Within an hour you could see that the black spots were almost gone and it was looking like new. I did this in the evening so am gonna leave on till morning and the rinse with a hose. If you want a clean patio don’t think twice and get this. Also I have still got a 5 ltr tub full so I can dilute this weaker for a maintenance wash as apposed to a deep heavy clean. So win win for me. Very very happy.also no jetwasher was required

Cleaned our fence and patio amazingly. Please note, always remember to mix this product 50/50 with water - if you need 5L overall....Mix 2.5L of the product with 2.5L of water to ensure you're not risking any accidents. The only reason we didn't give 5 stars is because the lids are a massive pain to open. Otherwise all good

I have tried all manner of cleaning materials with very limited success. Having tried this, I am amazed at the results. Fantastic cleaning power (I used neat on cotswold pavings and brick weave) and it's looks like new. I had to do a second spot clean in very few places which completely removed any trace of lichen. Highly recommended.

This is very strong stuff, wear gloves and protect your clothing. It worked wonders on my very grubby old patio and stripped the moss from the fence very quickly. It killed the weeds in between the paving slabs. I diluted 1:1 with water and just poured it on with a watering can. Then left it to do its job. Very impressed.

This stuff is amazing and was a huge help getting my patio clean to within an inch of its life. Would highly recommend this for an patio cleaning needed.

Using a chlorine solution is known as "Soft Washing". Called this because high pressure blasting isn't necessary to get an amazing visual difference in a short time.Two areas of Indian sandstone patio were looking a mess, I thought that most in the more shaded area would need to be replaced! Sandstone is soft and porous by nature, algae and lichen love the stuff.Sandstone is vulnerable to erosion, using a Karcher dirt blaster lance started to cause pitting in some of the softest areas of individual slabs and I was looking for a better way to defeat algae, Lichen etc.I knew that after a general wash down, bleach was the tool, but the domestic thin bleach is just 2% w/v of sodium hypochlorite (Hypo), which didn't work, even applied neat and left to soak.This Hypo is 15% when new, I made a solution with 50% tap water, sprayed it on the slabs and quickly noticed areas of small bubbles as organic residues were oxidised. After sufficient dwell time, it was rinsed well with a hosepipe.There was an amazing initial effect and for a few hours after rinsing, the slabs appeared to be getting cleaner still!It didn't cause any chemical staining of the sandstone and hard scrubbing was not necessary.Some of the more heavily affected areas had a slight visible residue of dead organic stuff! This will lose its grip after a few rain showers, washes and a re-treatment.Value for money lost a point because I purchased two 5L containers, a single larger container would be cheaper by unit, but it was my first trial of this specific product.Ease of use lost some points, only to highlight that it isn't something anyone can apply safely. It MUST be used and handled with great care. PPE should be used, access to areas being treated must be controled, pets must be kept away until it has been rinsed very well. There's much more to safety than these basic points, which aren't a guide.I used a backpack sprayer with an oval "drift guard" surrounding the nozzle, this stopped spray mist from being blown away from where it was being applied.

This liquid is the most effective way of removing green from stone flags. I’ve tried many other products but none work as well on stone. I think it’s sodium hypochlorite but I can’t read the product description. My dad was using it for years and said I should try it.I’ve got a cat and you shouldn’t let pets walk over it once it is brushed on the surface of the stone. I did the path in sections over several days and covered the treated section with thick plastic to protect the cat’s paws from any burning.Dilute to the correct mix then pour on the surface and brush into the surface if badly stained. Also brushing ensures even distribution. The results are amazing. Stone looks like new.