Refillable tanks collect more residue than pods because you refill them repeatedly and change coils by hand. The routine is similar, but you have more parts to dry.

• Empty leftover e-liquid and rinse the tank under warm water. Discard the old coil if flavor had faded.
• Wash the glass and drip tip with mild soap, then rinse until no soap film remains.
• Wipe the 510 threading and the mod's battery pin with a 70% alcohol swab.
• Inspect O-rings and replace any that are cracked, flattened, or stretched. Dry seals leak.
• Air-dry everything for 30 minutes before you refill. A wet tank spits hot e-liquid.

Store your e-liquid correctly while the tank dries. Heat and light degrade nicotine and flavor, so a cool, dark cupboard is the best place to keep bottles.