UK woman Serena Reynoldson, 35, was reportedly ‘furious’ her partner John Fitzpatrick had abandoned her and their five children after having an affair.
She filmed herself pouring the toxic bleach into his tank full of tropical fish, sending the footage via WhatsApp, The Telegraph reports.
‘Bleach, right in there, drink it good,’ she could be heard saying in the video.
‘Look they're drinking it. Die, die, die and die. If I can't have no hobbies or a life, you can't have them either and I'm not paying for it.’
Mr Fitzpatrick called the police on Ms Reynoldson and the RSPCA soon followed.
RSPCA prosecutor Simon White said the fish would have sadly ‘suffered’ before death.
Ms Reynoldson alleged her ex-partner had been unfaithful and abusive during their relationship.
The woman was handed down a sentence of 18 weeks, suspended for 12 months.
She was also banned indefinitely from owning fish and made to pay $746.