XMAX QOMO

The QOMO's cup holds only about 0.7ml and the glass carb cap sits directly over it, so an overfilled dab boils up and coats the underside of the cap rather than staying in the bowl. XMAX makes the same point in its own support FAQ: loading too much concentrate only makes it melt and splash. The bubbler is the other trouble spot, because it takes so little water that it discolours within a few sessions.

1. Change the water every session: Fill the borosilicate bubbler only to the red line on the side of the glass near the bottom. Tip it out and rinse it once you have finished, since the volume is small enough that standing water starts to affect the taste quickly. When the glass stains, lift it clear of its silicone collar and soak it in isopropyl until it runs clean.

2. Swab the cup before residue hardens: A cotton bud with a little isopropyl clears the bowl in seconds while it is still warm from a session. Give it a moment to cool first, especially if you have chained heating cycles, which XMAX caps at five in a row because the device gets very hot.

3. Look after the carb cap and its dab tool: The cap is thick borosilicate with a stainless pick set into it. Wipe the pick after each load so it does not glue itself down, and drop the cap into isopropyl once the glass starts to fog.

4. Pull the o-ring before soaking: The cap and mouthpiece joint relies on one small o-ring, which in our review looked like the part most likely to wear out. Take it out before any alcohol soak, rinse it under warm water, and fit the spare supplied in the box when the cap stops sitting tight.

5. Swap the atomizer rather than scrubbing it: The cup unscrews from the base and a replacement threads straight back in. Early units shipped with a ceramic disc, while the later quartz cup is sold as the easier one to keep clean and runs cooler for low temperature dabs.

6. Keep the base dry: The battery lives in a polycarbonate and aluminium shell that should never go near a soak, so a damp cloth is all it needs, and alcohol is best kept off the silicone. Charge over USB-C at 5V/1A or less, as XMAX says a higher input will damage the device, and leave it alone while it charges.