Its fine for plants Stu and I have used it on corys with no issues.
Dosing need not be that often... 2-4 ppm solution...dose 3 times... dose 1st dose ..24 hr bath...big water change ...redose about 3 weeks latter.. again 24 hrs bath...wc
.. redose a few months latter if you are the worrying kind.
Hth,
Al