A great way to anchor plastic plants and increase you pH and hardness all at the same time. I always keep a half gallon box of plaster of Paris in the garage. Takes about 5 minutes to mix the plaster in a bowl and stick a plastic plant in it.
Some more info at www.KoiVet.com if you want to dive into it.
Some more info at www.KoiVet.com if you want to dive into it.