ohh i get it now

i do that with my little goldfish sometimes
the old pond is sitting there with rainwater
theres so many mosquito larvae that
i just add a few fry in and usually
after a few days, theres none left
i get biten nearly every day(have a massive one behind my knee) because the mosquito stay around the pond as if to protect the larvae.
so how long can you leave them in pea soup

for
could they possible choke the fry?