My amazon sword has some algae on it so I took a gallon plastic bag and put the bag over the whole plant and squeezed most of the water out of the bag. The plant is still in the substrate the the bag covers it. I injected 15mls of the peroxide in the bag and closed it pretty well around the base of the plant. How long can I leave it like this? Will the plant be ok? I'm thinking of leaving it until I don't see bubbles anymore?