Why pour salt down the drain every night?

Why Salt Does Nothing

Salt does not dissolve fat, break down keratin, or remove mineral scale. Poured dry into a drain it sits in the trap until the next use of the fixture dissolves it and carries it away, which is the entire lifecycle of the ritual. The claims attached to the trend, that it melts grease or scours the pipe, describe properties salt does not have at the concentrations and temperatures involved.

It is not quite neutral either. Chloride is mildly corrosive to metal drain components over time, which matters in homes with older galvanised or cast iron waste lines, and on a private system a steady load of salt is not something you want reaching the tank. Neither effect is dramatic from occasional use, but a nightly habit is not occasional.

What People Are Actually Trying to Fix

Almost everyone who takes up a nightly drain ritual is responding to a smell, and the smell is real. Biofilm, a layer of bacteria and trapped organic matter, grows on the inside of the pipe just below the opening and in the crevices of the stopper assembly. It produces sulphurous gases, and no amount of running water removes it because it is attached to the wall rather than floating in the stream.

Two things genuinely address it. The mechanical approach is to pull the stopper out, scrub the visible pipe wall and the stopper itself with a bottle brush and hot soapy water, and put it back; this is unpleasant and extremely effective. The chemical approach is a bacterial enzyme treatment used overnight once a month, which digests the film rather than masking it. If the smell persists after both, the cause is usually elsewhere: a dry trap on an unused fixture, a venting fault, or debris sitting in a line that is draining slowly, and that last one shows up in the warning signs of a blocked drain.

The Rest of the Genre

The nightly salt routine belongs to a family of drain rituals that circulate in the same way: cola for rust, Alka-Seltzer and vinegar, salt with baking soda, pool shock. They share a structure, which is a dramatic visible reaction and no measurable effect on the material actually blocking the pipe. The two worth separating out are bacterial enzyme products, which are slow and genuinely work, and anything caustic, which works briefly and costs you pipe.

If a drain has moved from smelling bad to running slowly, the rituals have stopped being harmless and started being a delay. A single slow fixture is a plunger and a P-trap job. Several at once is a main line restriction, and that is what professional drain cleaning with a camera is for. There is a fuller treatment of what works and what does not in our guide to drain chemicals.

Why pour vinegar down the drain in October?

October has nothing to do with it. The trend circulates every autumn as seasonal content, and the mechanism it claims, that something changes in your plumbing in the fall, is not a real thing. There are two genuine reasons a drain gets attention at this time of year. Drain flies breed in the biofilm inside sink and floor drains through the warm months, so people notice them in late summer and autumn. And in a cold climate, fixtures that sat unused over summer, such as a basement floor drain, can have a dry trap and start letting sewer gas through. Vinegar will not fix either one. Flies need the film scrubbed out or treated with enzymes, and a dry trap needs a cup of water poured in.

If the autumn prompt is useful to you, keep the timing and change the task. Late October is a genuinely sensible moment in a cold climate to pour a jug of water into every floor drain and unused fixture so the traps are full before the heating season, to clear leaves out of exterior drains and window wells, and to run an enzyme treatment through the kitchen line before holiday cooking. Those are real seasonal jobs. Our note on clearing outside drains covers the exterior half.