Posted by Erika Rimkute
on June 09, 2026
You bought a diffuser. Maybe it came with a small bottle of lavender. Maybe it has been sitting on a shelf for three months, waiting for a moment that never quite arrived. Either way, you are probably not getting the most from it yet.
This is everything you need: how ultrasonic diffusers work, how many drops to use, how long to run them, how to clean them, and which blends suit which part of the day.
What type of diffuser do you have?
Most diffusers sold in the UK are ultrasonic diffusers. They work by vibrating a small ceramic disc at high frequency, which breaks water and essential oil into a fine mist that rises into the air. The room fills with scent without any heat — and that matters, because heat alters the aromatic compounds in essential oil and degrades the quality of the scent over time.
The other common type is a nebulising diffuser, which uses pressurised air to disperse undiluted oil directly, with no water. Nebulisers are stronger and faster but use more oil and run louder. They suit larger rooms or short, concentrated sessions.
If you have a reed diffuser, that is a different product entirely — no electricity, no mist, just liquid drawn slowly up through reeds and released into the air over weeks or months. Everything below is for ultrasonic diffusers.
How to fill your diffuser
Remove the lid and lift the cover from the water tank. Fill with clean, room temperature water to the fill line — never above it, because overfilling can damage the disc and reduce mist output. Add your essential oil blend directly into the water. Replace the cover, plug in, switch on.
Most ultrasonic diffusers begin producing mist within 30 seconds.
How many drops should you use?
For a standard 100ml diffuser in an average sized room, start with 4 to 6 drops.
A few things affect this. Room size matters — a large open kitchen needs 6 to 8 drops, a small bedroom or bathroom is fine with 3 to 4. Blend strength matters too, because some oils have a stronger throw than others. Peppermint and eucalyptus carry further than chamomile or geranium, so if your blend is heavy on those notes, start at the lower end. And personal preference matters most — some people want a quiet background scent, others want the room to feel noticeably different the moment they walk in.
The most common mistake is using too many drops. A concentrated scent in a closed room can feel sharp rather than pleasant. Start with less than you think you need, and adjust after your first session.
How long should you run it?
Thirty to sixty minutes is the most effective window for most rooms.
Your sense of smell adapts quickly to a constant scent — within about 20 minutes, your brain begins to filter it out. Running your diffuser for longer than an hour does not increase the effect. It mostly uses more oil.
For an evening wind down, the ideal is to start your diffuser 30 to 45 minutes before you get into bed. By the time you are ready to sleep, the room is already scented and the atmosphere is already shifted. You are arriving into it rather than waiting for it to build around you.
If your diffuser has an intermittent mode — on for 30 seconds, off for 30 seconds — use it. It scents the room more efficiently and makes your oil last longer.
Where should you place it?
Height matters more than most people realise. Place your diffuser at or above nose level — on a table, a shelf, or a bedside unit. On the floor, the mist disperses before it reaches the breathing zone.
A central position in the room distributes scent more evenly than a corner. Keep it away from direct airflow — next to an open window or under an air conditioning unit, most of the mist escapes before it does anything. And keep a metre or so of clearance from soft furnishings: fine mist over time can affect fabric.
How to clean it
This is where most people go wrong. A diffuser that is not cleaned regularly builds up oily residue that degrades the mist output, distorts the scent, and eventually shortens the life of the disc.
After each use, empty any remaining water, give the tank a quick rinse and dry with a soft cloth. Once a week, fill the tank halfway with clean water, add a teaspoon of white vinegar, run it for five minutes, then empty and wipe dry. This clears oil and mineral build up without damaging the disc. Once a month, use a cotton bud lightly dampened with rubbing alcohol to clean around the disc itself — this removes the residue that water and vinegar do not reach.
Never submerge the diffuser or put it in a dishwasher.
In the morning: Elevate
Five drops of Elevate as you get ready. The blend is lemongrass, peppermint, orange, mandarin and juniper — a bright, clean citrus scent with a freshness that is naturally uplifting without being harsh. It works in the diffuser as you move around the room, or on the shower floor if that is where your morning starts.
The practical instruction is simple. The more useful thing to know is that this is the blend that clears the air in a way that makes the morning feel different — not just scented.
At midday: Harmony
Harmony is the blend for the middle of the day. Orange and bergamot with geranium, lavender and rose absolute — warm and richly floral, with the bergamot keeping it bright rather than heavy. Five drops when you sit down at your desk, or when you step away from it for lunch.
The middle of the day is the part most people try to push through. Harmony is not about adding something to get through it. It is about a moment of actually stopping, even briefly, and letting the room change around you.
In the evening: Restful Sleep
Restful Sleep is for the bedroom, around thirty minutes before you want to sleep. Five drops of lavender, chamomile and eucalyptus. The eucalyptus keeps it clean and fresh so it never becomes the thick, heavy lavender that some people find too much. Easy to breathe in, which is exactly what the end of the day needs.
You can also use it on the shower floor in the evening, or add a few drops to a warm bath diluted in a carrier oil first.
A few common questions
Can you use too much essential oil?
Yes. Too much oil produces a scent that is more likely to cause a headache than create a pleasant atmosphere. If the room smells sharp or overwhelming, reduce by two drops next time.
Can you run a diffuser with just water?
You can, but it will only act as a humidifier. No scent, no benefit.
Can you mix different blends in one tank?
You can experiment, but two blends with competing scent profiles often produce something neither pleasant nor intentional. A blend like Aurey's is already balanced — no mixing needed.
How long does a bottle last?
At five drops per session, one or two sessions a day, a 15ml bottle typically lasts four to six weeks.
Is it safe around children or pets?
Some oils are not suitable around young children or cats. Eucalyptus is generally not recommended for children under ten. If in doubt, diffuse in a room away from pets and children, or check with your GP or vet before use.
The simplest way to start: fill your diffuser, add five drops of an evening blend, and run it for 45 minutes tonight. That is the whole habit. Everything else builds from there.
If you are not yet sure which blend is right for you, the guide to choosing between the three Aurey blends covers the scent character of each one in more detail. If you want to try all three, the Aurey collection has them together.
Erika is the founder of Aurey. You can read more about how Aurey began on the About page.
