What are the critters in my patio pond?

[VeryUninspired]

I have a small patio pond that is doing well, and is teeming with life of the very small variety.

There are a few mosquito larvae in there, but also many little round white swimming / diving things and also small, but longer silver things.

Any ideas? Thank you!

Photos would help! Daphnia?

in my pond I have umpteen daphne (water flea) whizzing about and also water slaters which look a bi like woodlice and all having a good time

Thank you and sorry for the delay. I think they might be water fleas as suggested?

Zoologist DH says ostracods - tiny crustaceans.