Reed Bed for Duck Pond Filtration

I am looking into designing a duck pond filtration set up using two 300 gal livestock water tanks I came into possession of.  One would become the new pond (a nice upgrade from our kiddie pool), and the other would provide filtration.  I have been unable to find any duckponics or duck pond filtration designs that incorporate reed beds, oddly enough, although I am sure reeds would do the job even better.  I won't go into the details of the actual design, but I am hoping to section off up to half of the filter tank to be used to grow watercress and duckweed (which may provide some filtration) for duck food before flowing into the gravel-filled reed bed section, as long as I have enough reeds to do the final job.  My goal is to provide a good deal of aquatic plant food for the ducks, but keeping the pond water clean has to be the highest priority given how much time, energy, and water this will save.  Would half of the 300 gal tank provide enough space for a suitable reed bed filter or should I maximize the amount of space used for the reed beds?  I suppose I could always add another smaller tank (which I would have to procure) for growing aquatic plants and just use the entire 300 gal tank as a reed bed, but I'd rather keep it small and simple if at all possible.

Thanks in advance for your thoughts and ideas!

I forgot to add that this is just for 6 ducks at the time being.

What an interesting concept. Why are you trying to filter the water? To be able to recirculate it and not have to add more water to their pool? I think you would need a pretty extensive/ expensive system to do that successfully.

I think the 300 gallon tanks are a huge boon, but I am dubious that they will provide enough space to filter water for 6 ducks. Ducks make some seriously dirty water that isnt easily filtered out. In a human blackwater system, the reed beds are elogated with multiple layers and pieces to the puzzle. The water has to be filtered multiple times over a distance. It is also filtered slowly and has a sedmentation area to drop solids. I think that with your two tanks you would be better off skipping the filtration idea.

Im not sure if you live in a place with decent rainfall, but the stock tanks would make good rain catchment to store water. You could have the water from the tanks slowly continuously flow into a duck pond/tank/ pool ( even the kiddie pools) and then attach a hose near the top to slowly drain out at the same time. This could give you some continuous cleansing flow without filtering. As long as you keep the flow pretty low, 600 gallons might get you a while. You would get more clean water days by filling and emptying the pool a couple of times a day. You could even get hose timers to do it for you. Duck poop water is fabulous for a gaeden bed, so you could direct it into your favorite bed of the day, and move the output hose( or even a soaker hose) as you want

Thanks for your reply Bryan.  To clarify, I am not intending for the filtration to be perfect, just to reduce how often I have to clean out and empty the pond water, while producing some aquatic veggies for the ducks.  I will definitely be using the pond water for the garden and would have to top it off when I do.  I guess I am drawing more from things I have seen about duckponics, but substituting reeds instead of regular veggies for the gravel filter beds.  Some of them seem pretty darn simple and appear to work pretty well even without reeds.

Some examples I have found:
https://www.youtube.com/watch?v=qOWFvvYH2CU#action=share
https://www.youtube.com/watch?v=_o36aZHKZl0#action=share  (my favorite, extremely simple yet functional)

I plan to use a "swirl filter" like the one shown in the 2nd video to remove solids initially.  That video uses an old bathtub as a pond, which are generally about 50 gal, which he then filters via 2 kiddie pool gravel beds (probably 25 gal each).  The difference with my livestock tank is that there is much less surface area in relation to the volume of the container, so I assume kiddie pools would be even better filtration.  But I have these tanks, and kiddie pools always seem to disintegrate after a season or two.  It is always possible that I just use the entire tank to grow aquatic plants and then just add kiddie pools until i am satisfied with the results.