Water rune

Ironman verdict

At least 9 monsters drop it. The easiest is Goblin (level 2, 6/128); the best rate is Maelstrom, Raging Waterfiend (level 142), at Always, about 125 per kill. You can also make it yourself: it takes 5 Runecrafting and gives 6 Runecrafting XP, using Rune essence. There are 2 other recipes below. Other sources include Essence impling, Essence impling jar, Ourania Runecrafting Altar and Wise Old Man/Tasks, plus 4 more listed below. Making ten takes 10 × Rune essence and gives 60 Runecrafting XP. Reaching level 5 Runecrafting takes 388 XP in total; the Runecrafting calculator counts the actions and materials to any target, and the Runecrafting guide has the Ironman training route. 113 recipes use Water rune, including Admiral pie, Alteration necklace and Amulet of bountiful harvest (new). Water rune is available on free-to-play worlds too. It is tradeable on normal accounts, but an Ironman cannot use the Grand Exchange or trade for it, so the sources on this page are the whole list. High Alchemy turns one into 3 coins, which is 14 less than the shop price, so buying it to alch does not pay.