What is the quickest way to get Void Salts in Skyrim?

Question

The other day I got the Nightingale armour and I have a pretty high smithing skill but I need Void Salts to upgrade the nightingale armour. Any suggestions?
I've tried looking at alchemy shops, my houses (Proudspire Manor, Hjerim and Honeyside), but none are there.

Answer 1

There is an overview on fandom.com of places where you can find Void Salts:

• Looted from Storm Atronachs.
• Can be very rarely looted from Falmer.
• Can be bought from alchemist's shops.
• Proudspire Manor alchemy lab in Solitude.
• Honeyside alchemy lab in Riften.
• Hjerim alchemy lab in Windhelm.
• Arch-Mage's Quarters in the College of Winterhold.
• Arcadia's Cauldron in Whiterun, on a shelf.
• Fletcher in Solitude, on a shelf.
• May be found in apothecary's satchels.
• May be awarded by Narfi at the end of his quest "The Straw that Broke."
• Can be obtained at Sky Haven Temple.
• Can be stolen in Calixto's House of Curiosities in Windhelm.
• In Sadri's Used Wares in Windhelm, on the shelves. He also sells this sample.
• 1 can be found in Valerica's Study in Castle Volkihar.
• On a shelf inside of Ragnvald Temple.

Note that this was the first hit when googling for 'Void Salts' - that was the 'quickest way' to get them. In-game, it depends on your character, and is therefore hard to answer.