You have probably seen adverts from companies claiming that they are selling some special formula for killing Moss and Algae.

The two biggest names in the industry being ‘Wet and Forget’ and ’30 Seconds’, that's probably how you ended up here! 

Both of these companies sell colourful bottles full of big promises but the truth is that these two products are using basic chemicals and the active formula in one is just as common as the others.

Wet and Forget and 30 Seconds use a range of chemicals, it is the concentrations that should be noted. It is best to find the Material Safety Data Sheet of Wet and Forget and 30 Seconds products, to compare the concentrations that are being used.

Most moss and algae products use 'Alkyl Dimethyl Benzyl Ammonium Chloride'also commonly known as 'Benzalkonium Chloride'Benzalkonium Chloride belongs to the quaternary ammonium class of biocides and is used in most moss/algae Killers. Benzalkonium Chloride is highly effective at controlling unwanted organic growths as it acts to keep the organic growths from returning for an extended period of time.

The only downside is the time it takes to get the results the average homeowner is looking for as Benzalkonium Chloride works over time. (Around 12-18 Months)

At the concentrations a lot of these products come in, it can take many months to kill moss, lichen, mold, algae, and fungi.

The other main chemical used for moss and algae treatment is Sodium Hypochlorite; a completely different active ingredient and far more well known.

Sodium hypochlorite, Bleach or Chlorine is a chemical that is used for a wide range of purposes; one of those being to kill moss, algae, lichen and fungi. Sodium Hypochlorite works incredibly fast and provides the instant results that most homeowners want. Sodium Hyperchlorite is easily washed away with a good rain shower and this will mean there is nothing to keep the organic growth away over time. Also Sodium Hyperchlorite at higher concentrations should be handled with extreme care. Will bleach coloured clothes.

It is hard to compare the two with each other because they are essentially doing different jobs.

In a perfect world, you would use both, one to kill the organic growth quickly and the other to keep it away. (Be careful not to mix the chemicals and wait for a good rain shower before applying to the same surface)

See below a list of commercial options for products at higher concentrations.