Put some Mosquitofish[1] into your pond. It should clean the pond up pretty quickly. It is also provide a pleasant environment as well, watching the fish rather than some box creating bubbles.
Mosquitofish were introduced directly into ecosystems in many parts
of the world as a biocontrol to lower mosquito populations which in
turn negatively affected many other species in each distinct bioregion.
Mosquitofish in Australia are classified as a noxious pest and may
have exacerbated the mosquito problem in many areas by outcompeting
native invertebrate predators of mosquito larvae.You should be able to use almost any local fish. We don't have malaria mosquitoes in northern europe, but when we just put some small perch (Perca Fluviatilis) and roach (Rutilus Rutilus) into a pond, they cleared up local mosquito larvae quite efficiently.
"Mosquitoes consume up to 300 millilitres of blood a day from each animal in a caribou herd, which are thought to select paths facing into the wind to escape the swarm. A small change in path can have major consequences in an Arctic valley through which thousands of caribou migrate, trampling the ground, eating lichens, transporting nutrients, feeding wolves, and generally altering the ecology. Taken all together, then, mosquitoes would be missed in the Arctic — but is the same true elsewhere?"
There seems to be this assumption that a small ecological disruption wouldn't cascade and to me that seems pretty short-sighted.
Yes, they're effective at containing mosquitos, but broader ecological disruptions can occur through other activities, including out-competing (or in cases eating) other aquatic life.
The same thing happened with bioengineered maize.