|Inputs (338,520)||Outputs (1,853,280)|
21,060 × Vial (42,120)
780 × Astral rune (296,400)
21,060 × Vial of water (1,853,280)
One can cast Humidify on an inventory of Vials. Use astral runes and equip a steam battlestaff to maximise profit and efficiency. Set up one of your "Quick Presets" to Withdraw 27 vials and 1 astral rune, cast the Humidify spell, which will cause the whole inventory to fill vials with water, open the bank, Click the Quick Preset and repeat. When playing at maximum efficiency, up to 780 spells can be cast per hour, for 21,060 vials of water.
Vials have a buy limit of 10,000 every 4 hours and it is not often that they will buy for 1 GP. Decanting plenty of potions is a fast way of obtaining vials. To decant, bring as many 3 or 4 dose potions to Bob Barter and select Decant-X and select 1 dose (make sure there are no empty vials). He will charge 2 GP for each Vial. Then select the Decant option from him and he will turn back all the potions to 4 dose then bank the excess vials. Repeat the same process as many times as possible. It is recommended to buy cheaper potions if you do not own plenty of potions. It is possible to profit or lose money from decanting, so be sure to pay attention to prices.
With the new Bank Improvement updates this can be done even faster resulting in more money and experience/hr. By setting the runes and vials as a quick preset, all you have to do is click the bank, click the preset, and click the humidify spell. This significantly lowers the click amount for this method.
The method above can be accelerated even further by binding Humidify to the same key as the quick preset. Click on the banker, press '1' (or 2, if that's what you chose), then '1' again.
Alternatively, casting Humidify on clay may be more profitable at 2,420,340gp an hour.