Why Washing-Up Liquid Kills Your Biocide

Mark Cave

So, you've- you've gone and spent your hard-earned money on a premium biocide, right? Something proper, like a DDAC or BAC50-based product, and you're standing there looking at the mix, thinking, "You know what? This needs a bit more cling. Let's get some bubbles going." So you reach for a bottle of standard, cheap washing-up liquid, or maybe some bargain-basement traffic film remover, and you squirt a generous dollop right into the tank. You think you're being clever, saving a bit of cash, making it look all nice and foamy for the customer. Well, let me tell you, you've just committed the absolute golden rookie mistake of exterior cleaning. You've- you've basically just neutralized your entire batch of expensive chemicals before it even touches the render.

Mark Cave

It- it all comes down to basic chemistry, and look, I'm dyslexic, so I don't do dry textbooks, but this is simple. It's like magnets. These quaternary ammonium compounds, the DDACs we use to kill off the moss and algae, they are cationic. That- that means they carry a strong positive charge. The reason they're designed like that is so they can lock onto the organic cell walls of the biofilm, which are naturally negative. But that cheap washing-up liquid? That's anionic. It carries a negative charge. So when you mix them, instead of the biocide attacking the algae, boom! The positive and negative molecules, they- they just absolutely lock onto each other like superglue. They- they clobber each other in the bucket.

Mark Cave

And the result of this little chemical clash is a right mess, fair play. They bind together and they actually precipitate right out of the solution. You'll see it sometimes as a sort of cloudy, waxy, inert residue. It looks a bit like jelly floating in your tank or clogging up your pumps. This stuff has zero biocidal power left. It- it won't kill a single spore. So you go ahead, you spray it all over the customer's roof or walls, it does absolutely nothing, and then three months later, you get that dreaded phone call. The algae is back, the customer is fuming, and you're looking at a massive, massive callback that's going to cost you time and money. All because of a squirt of washing-up liquid.

Mark Cave

Now, you're probably thinking, "Alright, Mark, how on earth do I get the solution to stick to vertical render without killing the biocide?" Well, the answer is simple, you need a non-ionic surfactant. Something like Clever Wash, which is what we developed and sell over at SoftWash UK. Non-ionic means it carries absolutely no electrical charge. It- it doesn't care about positive or negative. It just sits there, happily reducing the surface tension of the water, allowing that positive DDAC biocide to penetrate deep into the porous stone or render without getting neutralized. It gives you the dwell time, the safety, and the results, without any of the drama.

Mark Cave

But mixology is only half the battle, isn't it? We've got to talk about site compliance, because this is where the cowboys get caught out. When you're using DDAC or BAC50, you have a massive legal and moral responsibility. These chemicals are highly toxic to aquatic life. Let me repeat that: they are deadly to fish. So, you must never, ever let your wash-off or runoff enter a surface water storm drain. Those drains go straight to the local rivers and streams. You've got to use drain blockers, sandbags, whatever it takes to contain that runoff. If you need to discharge, it has to go into the foul sewer, and even then, you need consent from the local sewerage provider. If you're spraying on a windy day, you're risking drift onto the neighbor's prize roses, or worse, their pets. You've got to risk assess every single job, no exceptions.

Mark Cave

Look, this industry is changing, and the days of just "spraying and praying" with whatever cheap bleach you found in a barn, they are long gone. Chemical education beats trial-and-error every single day of the week. That's exactly why we set up the CPD Certified Softwash Training Course over at softwashing.uk. It's not about dry theory; it's about giving you the practical, real-world knowledge to mix safely, stay compliant with COSHH, and run a profitable, professional business that you can be chuffed with. Go have a look at the site, get yourself sorted, and let's raise the standards together. Right, that's me done for today. Take care out there, and I'll catch you on the next one. Bye bye.