I want to spend more time with submerged plants. They are the engine that makes the pond run properly. After submerged plants, I will talk about floating plants, marginals and emergents.
Submerged aquatics generally grow completely submerged. They are sometimes rooted in the pond bottom and sometimes float freely.
This is the anacharis or elodea we talked about yesterday. It is the most popular and widely used. It is invasive, but not as bad as hydrilla.
This is hydrilla, another underwater grass.
They look much alike, but if hydrilla is allowed loose in any fresh water anywhere, it will become a nuisance that will have to be dealt with by governmental authorities. If you see any anywhere for sale, please do not buy it.