Cleaning/preventing algae from path & patio?

Use dilute Jeyes fluid sprayed onto the algae.

It works well for moss too. Don't mix it up too strong on tarmac, it can soften it. Just apply it with a watering can or garden sprayer.

I think the commercial growers use a product called Abicide 82 for moss and so forth, algae is a different story, generally in very wet conditions like almost running water. If it realy is algae and not moss you might be able to kill it for once and for all with a dressing of powdered lime? depends on the eco system you are trying to destroy. Might be worth doing some googling, or asking the RHS at a local flower show.

You cant get Abicide in the likes of B&Q, but a good garden centre might be ale to get it. We last got some form a commercial garden supplier (Birkenhead, Wirral, but there must be others depending on where you live.

Or try

This link suggests that Abicide is what you want, but i cant vouch from experience with algae, it does work on moss though.

Cheers

John

Ah...that MAY be why I got a huge red algal bloom (thought it was blood!)in the puddles on my sandstone after I brick acid-ed it..:-)

So it don't like alkali?

Bleach or caustic then. Lime will ruin the appearance..

I can't understand quite why the algae returns within days, but household bleach would work by killing the algae spores. There are specific algaecides from companies like Quadralene.

Jeyes fluid works for about two to three months depending on recurrence of dampness. Spray on with a watering can. Keep pets off it for 12 hours Paul

I use a product called Dax Fungo.

I have no connection with this company. Just a satisfied user.

Hi, When I was at fish camp (remote fish processing village on the west coast of Canada) we found the wooden docks to be very slippery. The companies solution was to put salt down on the docks. That cured the algae from forming. You could try a small section to compare with the other solutions provided from other people. Salt is cheap but leaves a white film. I hope you find a satisfactory solution.

Wouldn't salt eventually adversely affect the concrete?