Several other folks use it and it's killed their Riccia, I've used it on other liverworts specifically and it killed it in a few days.

If you are dosing at the lower end, it might not kill it.
I'd suggest easing into the use if you have sensitive plants.

Others have reported rapid death of their Riccia when used.
I guess I'll have to test it myself specifically.



Regards,
Tom Barr