Custom Chemical Supplies Sodium Hypochlorite 14-15% 4x5L, Patio Cleaner | High Strength, Swimming Pool Chlorine, Pale yellow (SH1415-20)

Here's what worked for me. I removed the mud from my blick driveway pointing, then used a jet washer to blast the bricks clean. The black spots refused to budge.Much to my surprise - you have to be sceptical right - this cleaner worked like a dream! I simply used a watering can & a 50 / 50 water mix, and sprayed away!The black spots either disappeared or evolved into grey marks, which another jet wash removed easily.Highly recommended, both for its effectiveness and for ease of applying.

Works well undiluted on very dirty patio with black spot. Does not get well rooted black spot off but makes a big difference. Second coat makes no difference so I reverted to metal brush in places. Definitely use PPE as very corrosive and smells very strong. Would definitely use again, good value for money and well more effective than weaker rubbish sold as miracle patio cleaner.

Great product for cleaning algae, killing moss and paving slabs. No longer need a pressure washer after using this product. Excellent and will keep buying.

I liked it as worked as advertised And killed the weeds. No jet washing from now on.

This was my first time using hypo. I went with a 5:1 ratio on a sandstone patio. It was a warm day so I couldn’t let it dwell as long as I would on an overcast day.The result is very good, most of the grime and black spots have gone after just one application.Splashes will ruin your clothes, as others have written, use PPE and wellies.

Very good product!

Patio looks nice and clean with no effort

Excellent service and product could not be happier 😊