Quote Originally Posted by Snapshot View Post
As "penta" would likely indicate a pentahydrate
form of sodium thiosulfate (having 5 water molecules),
you would need more of it than the anhydrous or
dessicated form of sodium thiosulfate. Other
than that chemical difference, they should
work the same.
Very nearly 50% more of the penta; all that H2O.
Dissolving the penta causes the solution to chill.
That is one way to tell the two apart.

I add a measure at processing time to the needed
volume of water. Easy fresh fix. Dan