'SSIC - Standard Subject Identification Code', All Acronyms, 17 January 2018, <https://www.allacronyms.com/SSIC/Standard_Subject_Identification_Code> [accessed 17 January 2018] Bluebook All Acronyms, SSIC - Standard Subject Identification Code (Jan. 17, 2018, 12:01 AM), available at https://www.allacronyms.com/SSIC/Standard_Subject_Identification_Code. CSE All Acronyms. SSIC - Standard Subject Identification Code [Internet]; January 17, 2018 [cited 2018 JAN 17].
Set your timer for 1 minute and wait. You can keep the etching cream on the glass longer and you will get a more intense etch, but the manufacturer (and I) suggest you start with the recommended 1 minute. When the minute is up, run the glass under luke warm water to remove the etching cream.
The glass can be refilled again and again with additional water and salt crystals as needed to keep this process going. As long as you have solid crystals in the bottom, and the solution has sat for at least twelve hours, you can be assured that you have a 26% solution.