Elemental Siphon is a Summoner Job ability gained at level 50 in Final Fantasy XI. It allows them to drain MP from an elemental spirit under their control.

• Recast Time: 5 minutes
• Can only be used with an elemental spirit summoned. It does not work on avatars.
• The effectiveness of this job ability is dependent on the in-game day of the week, the current weather conditions in the area where this ability is used, and the Summoner's Summoning Magic skill.
• Summoners will get the most MP recovery when used on an elemental that matches the weather or day.
  • Example: using Elemental Siphon on Air Spirit on Windsday during windy weather provides much better MP return than using Elemental Siphon on Fire Spirit on Watersday during rainy weather.
• The following Scholar spells affect the MP regained through Elemental Siphon:
  • Aurorastorm
  • Firestorm
  • Rainstorm
  • Sandstorm
  • Thunderstorm
  • Voidstorm
  • Windstorm
• Elemental Siphon can be used on the following summons:
  • Air Spirit
  • Dark Spirit
  • Earth Spirit
  • Fire Spirit
  • Ice Spirit
  • Light Spirit
  • Thunder Spirit
  • Water Spirit