Jarder 2 x 5 Litre Concentrate Spray & Leave Cleaner - Patio Fencing Decking - Green Mould & Algae Remover

My backyard is around 30m2 and fully concreted. It had been over 3 years from I last cleared it of the green algae, it had a very thick covering and had turned black in places. I know it says to add 4 litres of clean water to 1 litre of it. I tried this concentration and then tried 2 litres plus 3 litres of water, both these weren't strong enough to cut through the algae growth. I ended up using a 50/50 concentration and 1 x 5 litre container was enough to cover the backyard. After 24hrs you could see a big difference and after 48hrs the backyard was completely cleared and cleaned of the 3+ years of the algae growth. That was just over 2 months ago and the yard is still clear of algae with no signs of growth back yet.

Pretty good stuff - cleans off algae after a few days and kills any moss in cracks; however, only seems to affect algae not darker lichen (or whatever) spots. First image shows difference where I didn't spray lest I might harm a nearby plant - this was just a single application; second image shows a cleaned area, but shows the dark spots that were unaffected (note different slabs are more or less prone to these darker spots; and mainly near the edges). I should note that this is pretty much the same effectiveness as using a power-hose, but easier to apply, though will need to see whether this is as long-lasting as others have implied (with power-hose needs doing every 3-4 months). This is definitely easier on the paving (or the cement between slabs) but need to see whether it affects nearby plants or not (for good or ill). [Update almost a year on] Well it lasted well, but when I resprayed this time it appeared to have no affect at all. Perhaps I needed to shake the liquid well before pouring out to mix. Will have another bash soon and report back. So I wonder if it needs to be used shortly after receiving it so only buy enough for immediate use.

Great product which did exactly what it was supposed to do. We had a green algae on our driveway and path, covering a large area. I applied the product using a 5L pressure sprayer and concentration of 5:1 and the green was completely gone within 5 days. Will definitely use again.

I was pleasantly surprised as this worked exactly as described. I sprayed my green covered wooden fence and when dry its back to original colour wood. Has stayed clear of the horrible moldy green for some time too. Noticed a slight improvement on my stone blocks but staining was quite severe because area is always in the shade and stays damp. Might need to use stronger concentration and more often in this area.

Great value for money 💰

This does exactly what it states on the instructions for use , my caravan roof was well infested with green algae one application before rain as instructed on container, walked away returned after 2/3days algae gone,a quick soap and water, back to it's former glory days, Saved a lot of hard work

Did a power wash on my very dirty slabs before using this. I left one 'unwashed' to see what this treatment actually did. Couldn't see any real difference (slap was still stained) so I power washed it later, then reapplied the treatment. As I followed the instructions to the letter and left it on a couple of days, I may see the value in time. Perhaps it will reduce moss, algae and general staining. Only time will tell.

Works really well if you bother to read/follow instructions. Removes green algae/moss from all outdoor surfaces, we use it all year round because of our rubbish weather in UK, mostly so when rain leaves everything green after a while. We generally use it every two or three months or if it needs it. All in all its great stuff. Update: I forgot to mention, it works so well that my neighbour 2 doors up asked what we were using. He saw my husband spraying out front where we get extremely bad algae and moss (we get no sun out front); he was totally amazed that it had died and had practically vanished 3 days later. We are pensioners and as this neighbour helps my husband with tough jobs from time to time, my hubby sprays his area as well as an elderly lady's next to him. We can only say that if it's not working it's not being applied under the right conditions or the correct strength. It really has to be applied when ground is dry and no rain for a day or so after application. Hope these additional comments help. Do not get spray on plants or in water left out for wildlife!