Clearomiser - Understanding tank vaporisers for e-cigarettes

A clearomiser is a vaping unit with a transparent tank made of glass or plastic, which is screwed between the battery mod and the mouthpiece. Inside is a replaceable atomiser head (coil), consisting of a heating wire and an absorbent wick – usually organic cotton. The wire heats the e-liquid, which is drawn into the wick by capillary action, and turns it into vapour.

Unlike an RTA (Rebuildable Tank Atomizer), with a classic clearomiser e-cigarette setup you don’t have to wind coils yourself. You simply replace the pre-made atomiser head as soon as the flavour starts to fade. Typical components of a clearomiser are: a base with a 510 thread, a tank (usually 2 ml in accordance with the TPD; larger tanks in accordance with EU/CH regulations with a bypass option), a chimney tube, a coil holder, an airflow ring and a drip tip as the mouthpiece. Many modern models use a top-fill system – you unscrew the mouthpiece and refill the liquid from the top.

The tank vape works on a simple principle: the battery supplies power, the coil heats up, and the e-liquid vapourises. The coil’s resistance (measured in ohms), together with the power of the battery mod (in watts), determines the vapour production and the flavour.

MTL – mouth-to-lung

Clearomisers with a tight draw and coils between 1.0 and 1.8 ohms are suitable for MTL vaping, which resembles the draw of a cigarette. Typical power: 10–20 watts. Ideal for nicotine-containing e-liquids with 10–20 mg/ml.

DL – Direct Lung

Sub-ohm clearomisers with resistances below 1.0 ohms and a wider airflow deliver dense vapour at 30–80 watts. Suitable for short fills with a low nicotine content (0–3 mg/ml) and a higher VG content.

In Switzerland, a clearomiser usually holds 2 to 5 ml of e-liquid. Depending on the coil type and vapour production, one fill-up lasts from a few hours up to a whole day. The coil itself typically lasts 1 to 3 weeks before you should replace it.

Before choosing a pre-built atomiser, it’s worth taking a look at the key criteria. Not every clearomiser suits every mod and every vaping style.

• Coil availability: Check whether replacement coils will be available in the long term. Proprietary systems are convenient, but dependent on the manufacturer.
• Draw characteristics (MTL vs. DL): A tight draw for those switching from cigarettes, an open draw for cloud chasers. Many models offer adjustable airflow rings for both options.
• Tank capacity and material: 2ml tanks are sufficient for short sessions; 4–5ml tanks reduce the need for refilling. Glass is more flavour-neutral than plastic.
• Filling: Top-fill systems are more practical and leak-proof than bottom-fill designs.
• Compatibility: Check for the 510 thread and the recommended wattage – a sub-ohm clearomiser on a weak battery will produce hardly any vapour.

A common mistake is not priming the coil when filling for the first time: apply a few drops of e-liquid directly onto the cotton and wait 5–10 minutes before vaping. Otherwise, the cotton will burn and the coil will be ruined.

How often do I need to change the coil in the clearomiser?

Every 1 to 3 weeks, depending on the e-liquid and how often you use it. Sweet or heavily coloured e-liquids shorten the coil’s lifespan. A burnt, charred taste is a clear sign that it needs changing.

What is the difference between a clearomiser and a pod system?

A clearomiser is a standalone tank with a replaceable coil that screws onto a battery mod. A pod system is a closed or semi-open cartridge, often found in more compact devices and frequently optimised for nicotine salt e-liquids.

Can I use any e-liquid in a clearomiser?

In principle, yes, as long as the VG/PG ratio suits the coil. Sub-ohm coils can handle high VG ratios (70/30), whilst MTL coils work better with more balanced mixtures (50/50). Nicotine salts are primarily intended for MTL setups.

Why is my clearomiser leaking?

Usually, the coil isn’t screwed in tightly, the seals are worn out, or the tank has been overfilled. Also check that the airflow ring is closed when filling.

For many vapers, a clearomiser is the practical middle ground between low-maintenance disposable devices and professional rebuildable atomisers. If you understand the basic principles of coil resistance, airflow and e-liquid composition, you’ll get significantly more flavour and runtime from the tank. Take your time to browse the range of vaporisers, compare MTL and sub-ohm models, and add suitable coils or a new e-liquid if needed. Products containing nicotine are intended exclusively for adults aged 18 and over.