ULTIMA-PLUS XP Green Mould and Algae Killer Patio Cleaner Simply Spray Leave and Walk Away Green Mould and Algae Killer for Patios, Fencing and Decking 5 Litre Concentrate (Makes 25 litres)

There’s a lot of these types of products out there, but I keep buying this one because it’s so effective at getting rid of algae from our driveway, fence panels and patio. I use this on block paving, porcelain patio slabs and wood fence panels/gates. I’ve used this on redwood decking that is also highly effective.

Spray it when you have 3 days of no rain to insure it penetrates the ground.

Sprayed this over porcelain slabs & within two days the green mould that had built up over winter was gone . Never scrubbed it just sprayed on & left , worked on wood garden sleepers too

Applied it 3 times. Exactly as instructed during low light. And its worked on some moss on the fences well. But plants and algie and black mould all still between my paving slabs. My first application was as instructed, 1l added to 9l water, second application was 2l added to 8l water, 3rd application was neat which seemed to work. But £20 odd for 5l to barely work is NOT worth it. You're much better off with strong bleach as it would also brighten the stone too. I just bought some with 15% sodium Hypochlorite and its epic. Even removes black lichen spots.

An addendum to my last review - as I noticed that this stuff continues to work for up to 6 months. Blackened tops of pillars are now back to their original beige colour. Block paving is much clearer and lighter in colour against untreated paving that looks black and slippery. Moss and green mound on my roof where water runs off stays aways for a good 6 months after applying. I’m buying it again! This stuff really does work if applied in dry conditions. The downside is that it too 2-3 weeks before you could really see the difference - but it has definitely worked. I had identical green moss on my roof to that of my 2 neighbours (same style house) and 3 weeks later and mine has all gone and theirs is still there! Very easy to apply, and does exactly what it claims to. For very bad areas it may need another application - and on block paving was a little harder to see the results - but where it was slippery it isn't anymore

This was recommended to me by a friend, and after reading some reviews (we do tend to focus on negatives at times) I was thinking it would take up more time and product for the result I wanted than actually happened. I used this on our garden fence and an area of our driveway that tends to grow algae due to being shaded more than the rest of the area and within 24hrs the green on both the fence and the drive was a dull tan colour without any damage to the surrounding area, it effected the algae and nothing more, with the fence being able to be painted after a light brush off of the algae remains the next day. Easy to use, just ensure you mix well and buy a good sprayer and the jobs done.

I sprayed a solution of this product onto my porcelain stone patio using a hand pump sprayer. There was no initial change and I thought the product wasn’t going to work. However, some 4 hours later all the green algae had disappeared. I’m very impressed.

I have only tried a small area with Ultima Plus xp, as the weather is not giving me a big enough window to treat my whole shed,, The guide lines advise that the algae/ moss killer works best over three dry days,, however I got a day and a half, free of rain,and I could see that the product did remove the algae on the small area which I treated,, so far impressed and delivery was very fast, so an easy 4 stars, perhaps 5, when I try it out further