I'm looking for suggestions for very small and short, very cold, zone 5 (if possible) water plants. I have a very small water feature, recently turned into a very small, shallow (normally about 5 inches deep), narrow fish pond. It's max length is about 6 feet and max width about a foot and a half. (it was/is a rock pond completely filled with river rock, then water added to fill in, along with a large drilled rock for the water to pump out for a little fountain look. I kind of opened up space for the water depth.
The large wet rock is where the water comes out for the fountain look, only shoots out about 5 or 6 inches and the large dry square looking rock sits on top of the pond pump and filter. (in the picture)

There are, at least four little feeder fish (rosy red barbs) that did survive over wintering this year. These little fish don't show themselves very much, so trying (hoping to get them out more) to maybe get them to come out more?
When I completely fill the pond with water, it's depth is about 9 to 10 inches in depth at its deepest point (just below the big wet rock in the picture), but that drains down within a few hours to the 4 to 5 inch depth and sort of stabilizes at that depth.


Thx.
The large wet rock is where the water comes out for the fountain look, only shoots out about 5 or 6 inches and the large dry square looking rock sits on top of the pond pump and filter. (in the picture)

There are, at least four little feeder fish (rosy red barbs) that did survive over wintering this year. These little fish don't show themselves very much, so trying (hoping to get them out more) to maybe get them to come out more?
When I completely fill the pond with water, it's depth is about 9 to 10 inches in depth at its deepest point (just below the big wet rock in the picture), but that drains down within a few hours to the 4 to 5 inch depth and sort of stabilizes at that depth.


Thx.