Sub-ohm tanks explained: big flavour, big clouds and what you need to run one

On the outside a sub-ohm tank looks like any tank: a glass section with a drip tip on top and a 510 thread underneath. Inside, everything is scaled up. The coil heads are wider, the wicking ports are larger to keep up with thick liquid, the chimney is broader and the airflow slots are big.

When you inhale, air rushes in through the airflow ring, passes over a hot low-resistance coil and carries a large amount of vapour straight up the chimney into your lungs.

Every part is designed for volume. That is why sub-ohm tanks feel so different from MTL ones, even though the basic layout is identical.

Our tanks section includes several dedicated sub-ohm options. The Geekvape Z Subohm Tank 5, the Voopoo Uforce-X and the Innokin Z Force are all built around mesh coils for direct lung vaping. The Voopoo PnP X DTL pod tank brings PnP X coils to a 510 mod.

Sub-ohm tanks tend to be wider than MTL tanks, typically 24 to 27mm in diameter. That matters when you pair one with a mod, because a tank wider than the mod's top plate overhangs, which some vapers find untidy.

The bars show the diameter of a few examples, taken from our listings.

Most sub-ohm coils sit between 0.15 and 0.4 ohm and want somewhere between 25 and 70W. That is beyond most pod kits, so you need a box mod with a 510 connection.

A single-battery mod handles 0.3 to 0.4 ohm coils comfortably and copes with lower ones in shorter sessions. For the very lowest resistances at high power, a dual battery mod lasts much longer between charges.

Our mods section runs from compact 40W options like the Vaporesso GTX One Pro to 220W dual battery mods like the Voopoo Vinci Spark220. Check the maximum wattage against your coil range.

Sub-ohm tanks are made for thick liquid. A 70/30 VG/PG ratio is the standard, and 80/20 works well in tanks with large wicking ports. Thin 50/50 liquid can flood a sub-ohm coil and leak from the airflow.

Nicotine strength needs to come down. Because each puff carries so much vapour, strengths of 3 to 6mg feel similar to much higher strengths in a pod. Nicotine is addictive, and a high strength at this vapour volume is unpleasant and harsh.

Most sub-ohm vapers buy shortfills, which come at 0mg with room to add a nicotine shot. Our 70% VG range is a good place to browse.

Setting up a new sub-ohm tank is straightforward, but a few habits make the difference between smooth clouds and a leaky mess. The checklist covers what to get right on day one.

The biggest one is priming. Sub-ohm coils carry a lot of cotton, so prime generously and wait the full ten minutes with thick liquid. Then start at the bottom of the coil range and work up.

Keep the airflow open while vaping. Choking a sub-ohm coil traps heat and can cause dry hits. If you want a tighter draw, a higher resistance coil or an MTL tank will serve you better.

Sub-ohm vaping is a great experience when the whole setup matches, and a frustrating one when it does not. Usually, a problem comes down to one mismatched piece: the wrong liquid, not enough power, or too much nicotine.

When something goes wrong, check those three first. If the tank spits, our guide on why a coil spits helps. If it leaks, the guide to filling a tank without flooding covers the usual causes.

One question to finish, based on the most common sub-ohm complaint we hear about: a tank that gurgles and weeps liquid out of the airflow slots.