Question
Dont know if im in the wright section here but. I live in  England and ive recently just upgraded a gravity filter in my pond.The ghost Carp are getting big. I had to cut back a few Iris to get it looking ok. Ive noticed these little fly things id say about a centimetre long a bronze shiny body and 2 clear wings with black tips at the end. Ive noticed them at the pond before but they havent really been a problem just after doing my filter theres loads of them. Ive got a waterfall and cleaned it becuase i use it as a naturual filter with gravel. It was full off pond sludge as you would expect. I think with disturbing they just swarmed for the waterfall. There not a problem as such becuase they stay next to the pond. Just wondering if you had any idea what they were.

Many thanks for your time and help

Andy

Answer
Sounds like one of the dragon flies.

A dragonfly is a type of insect belonging to the order Odonata. It is characterized by large multifaceted eyes, two pairs of strong, transparent wings, and an elongated body.

Dragonflies typically eat mosquitoes, midges, and other small insects like flies, bees, and butterflies. They are therefore valued as predators, since they help control populations of harmful insects. Dragonflies are usually found around lakes, ponds, streams and wetlands because their larvae, known as "nymphs", are aquatic. Dragonflies do not bite or sting humans.

There is actually a British Dragonfly Society . They say there are 34 different species of dragon flies in the UK.

http://www.dragonflysoc.org.uk/home.html