Submerged water plants : The plants that produces oxygen under water Plants that produces oxygen under water to help keep the pond in balance. Should be planted completely submerged. Submerged water plants are the unsung heroes in the war against green water, the one battle all pondkeepers are sure to face sooner or later. Important to water quality as well as water clarity, underwater plants help filter unwanted nutrients and add important oxygen to the water during the day. Besides their Read more