I bought a bottle of Cloverleaf Absolute Clear to get rid of the algae in my new pond, and can’t work out how to open the bottle! It has two apertures with screw top caps, and at the moment I haven’t got a drop out of it in case I’m doing something wrong. Do I just get a lid off and measure some chemical into an old receptacle which I then tip into the side of the pond, or do I somehow extract some of the pond water and dilute the chemical with that before adding it back to the pond? There are no instructions on the bottle. Help!!!