Bottom feeder - Understanding, using and maintaining squonkers

A bottom feeder – often also called a squonker or BF mod – is a type of mod in which the housing contains a soft plastic or silicone bottle (usually 6 to 10 ml) in addition to the battery. This bottle is connected to the screwed-on atomiser via a special 510 connection with a through-hole and a flexible tube.

If you squeeze the bottle sideways through a recess in the casing, e-liquid is forced upwards into the atomiser chamber. When you release it, the bottle draws excess e-liquid back in – the cotton remains saturated but not flooded. The bottom-feed system thus replaces the traditional dripping method used in RDA vaping. Important: Not every atomiser is compatible with bottom-feed systems. You need a so-called BF-RDA or BF-RDTA with a special 510 pin that directs the e-liquid upwards into the coil chamber.

The process is straightforward: insert the bottle, fill with e-liquid, screw on the BF atomiser, insert the battery. Before taking your first puff, give the squonk button a quick press until the cotton is visibly saturated. Then vape as usual, and every few puffs give the bottle another quick press – usually half a pump is enough.

Mechanical vs. regulated squonkers

Mechanical squonk mods have no electronics. The power output depends directly on the battery charge level and coil resistance. They are aimed at experienced vapers with knowledge of Ohm’s law. Regulated BF mods feature a chip that offers wattage control, short-circuit and overheating protection – the safe choice for beginners.

Typical applications

Bottom feeders are primarily used by DIY coil builders who run sub-ohm setups with 0.1 to 0.4 ohms and power outputs between 40 and 90 watts. Thanks to the integrated bottle, there is no need for a separate e-liquid bottle when on the go, making the squonker a practical companion.

A suitable squonker must suit your vaping style, your atomiser and your safety preferences. These points are crucial:

• Battery configuration: Single 18650 mods are compact and sufficient for moderate power. Dual 18650 or 21700 variants deliver more power and longer runtime – useful from around 60 watts.
• Bottle material and size: Silicone bottles feel pleasantly soft and dispense e-liquid more precisely. 7 to 8 ml is a good compromise between size and capacity.
• Regulated or mechanical: For beginners, a regulated BF mod with safety circuits is essential. Mechanical squonkers require specialist knowledge of battery safety and coil building.
• BF pin compatibility: Check whether your chosen atomiser comes with a BF pin included. The system won’t work without a matching 510 pin.
• Build quality: A tight bottle compartment, a clean feed tube and a sturdy push button prevent leaks and air bubbles.

Also, avoid common mistakes: pressing too hard floods the coil and causes gurgling, whilst squonking too infrequently allows the cotton to dry out and burn. With a bit of practice, you’ll usually find your rhythm after just a few fills.

Is a bottom feeder suitable for beginners?

Yes, provided you choose a regulated squonk mod with a protection circuit and already have some experience with coil building. Pre-made coils are rarely available for BF vapes – so a willingness to tinker is a prerequisite.

Which e-liquid is suitable for the bottom-feed system?

VG-heavy e-liquids (at least 60% VG, usually short fills) are suitable, as they are designed for sub-ohm vapes. Very thin 50/50 e-liquids may drip through the feed tube. Nicotine is intended for adults aged 18 and over only.

How do I clean a squonker?

Empty the bottle, rinse it out with warm water and leave it to dry completely. You can clean the feed tube with a cotton bud. The battery and electronics must, of course, remain dry.

Can I use any RDA on a BF mod?

No. You need a BF-compatible atomiser with a drilled 510 pin. Many modern RDAs come with both pins, so you can switch between standard and squonk mode.

A bottom feeder combines the flavour intensity of an RDA with the convenience of a tank – ideal for vapers who build their own coils and don’t want to be constantly topping up whilst on the go. The key factors are a suitable BF atomiser, the right choice of battery and a bit of practice with the squonking rhythm. If you’re interested in this kind of setup, you’ll find suitable devices in our range of mods, as well as complementary coils and building accessories – take your time to compare the designs and choose the model that suits your vaping style.