My search did not find anything, but I can't imagine I am the first to discover this small omission in the alchemy process. There is no poison that is level-equivalent to Cloud Mist (Solvent proficiency rank 6). There are 9 waters divided over the character levels, but only 8 poisons. Why the difference? Accident? Working as intended?
(50) Quigster Bosmer Stamplar
(50) Lorithar Lightcrest Altmer Mag Sorc
(50) Tanius Magnitus Argonian Magplar
(50) Kalethar Redguard Stamplar
(50) Ra'Jo Darkstrike Khajiit Stamblade
(50) Gen Maximus Imperial Stam DK
(50) Jakon Fenrif Redguar Stam Sorc
(50) Revus Meredor Dunmer Mag DK
(50) Gorath the Silent Orc Stamblade
(31) Bjorn Ironhand Nord Stamplar
(28) Lord Devin Woodhearth Breton Magblade
Altaholic, CP 600+