Three drops, not six

Ten millilitres does not look like much when it arrives. It is a small bottle, and the instinct on the first evening, when you want to know what you have bought, is to be generous with it.

Be generous once. Then stop.

The arithmetic

A 10 ml bottle holds somewhere between 200 and 250 drops, depending on the viscosity of the oil and how steady your hand is. That gives you this.

Drops per session	Sessions per bottle	Used once a day
3	about 75	10 to 11 weeks
5	about 45	6 to 7 weeks
8	about 28	4 weeks
12	about 19	under 3 weeks

The difference between three drops and twelve is the difference between a bottle lasting a season and a bottle lasting a fortnight. We say six to eight weeks on the product page, and that assumes three to six drops on most days. Somebody using twelve drops twice a day will empty it in ten days and conclude, quite reasonably, that we are expensive.

Why more is not better

There is a threshold above which a room does not smell stronger, it just smells thicker. Fragrance in a cold mist behaves differently from fragrance in a candle. There is no combustion to burn off the heavy notes, so everything you put in stays in, and the light top notes that make a scent feel fresh are the first to be buried.

Overdosing an ultrasonic diffuser does not make a room smell of more. It makes it smell heavier, flatter, and less like the thing you liked in the first place.

In a Maltese summer this happens faster than it does elsewhere. Rooms are warmer, so the oil volatilises quicker, and the windows are shut, so nothing leaves. A dose that is pleasant in a ventilated room in April is oppressive in a sealed room in August.

A dosing guide that actually works

• Small bedroom, door shut, summer. Two to three drops.
• Living room, average Maltese flat, summer. Three to four drops.
• Living room in winter, windows shut. Four to six drops.
• Open plan, or a room with a stairwell. Five to six drops, and run it for longer rather than stronger.

If you want a room to smell of something all evening, the lever to pull is time, not dose. Three drops running for two hours gives a steadier and more pleasant room than eight drops running for forty minutes.

The other reason to go light

Your nose stops registering a constant smell within about fifteen or twenty minutes. This is not a fault, it is simply how olfaction works, and it is the reason you cannot smell your own house. The practical consequence is that the person adding more drops because they cannot smell it any more is usually adding them to a room everybody else finds strong.

The way around it is not more oil. It is to run the diffuser for thirty or forty minutes rather than continuously, and let the room settle afterwards. You will notice it again every time you walk back in, which is the entire point.

Practical notes

• Fill the tank with water first, then add the oil. Oil onto a dry disc is the fastest way to a film you then have to clean off.
• Changing scent? Rinse the tank. Bajja on top of yesterday's Xlokk is not a third scent, it is a muddle.
• Keep the bottles upright, capped and out of direct sun. A bottle left on a sunny windowsill through a Maltese July will turn faster than one kept in a drawer.
• Every bottle carries a best before date on the label. One in daily use will be long gone before it.

What that means in money

Used the way we intend it, one 10 ml bottle is roughly six to eight weeks of most evenings. The Signature Three, which is all three scents at 10 ml each for 17.90 euro, is therefore something like four to six months of a good smelling house. Used twelve drops at a time it is about six weeks.

The bottle is the same in both cases. The habit is the only thing that changes.

One more habit worth keeping alongside it: a weekly wipe of the ceramic disc, because Maltese water is hard and scale is the real reason diffusers seem to fade. The method is in Hard water in Malta and your diffuser.