Melissa Swift, 24, admitted three counts of attempted murder after an investigation into her conduct at the Goldfield Court home in West Bromwich.
She was made the subject of an interim hospital order after a judge heard she may have a mental disorder.
Swift is expected to be moved to Rampton Hospital within 28 days.
The former special constable with West Midlands Police, from West Bromwich, admitted three charges of attempted murder and two counts of making threats to kill in February.
Everyone at the home had access to the drinks containing bleach, 25 residents and seven staff were taken to hospital.
She also sent anonymous letters to two other members of staff threatening to kill them, including one to her older sister.
Birmingham Crown Court heard Swift is due to be sentenced later this year.
Judge Philip Parker QC granted an interim hospital order lasting up to three months.
Rampton Hospital is a high security psychiatric facility near Retford, Nottinghamshire.
A woman who used bleach to poison colleagues at a West Midlands care home is to be admitted to a high-security psychiatric unit.