Pet wrote in message ...
Simon Avery wrote:

Sound like midge larvae. Won't harm your fish, but if they get washed
into the pond they might make 'em fatter.


Just found this
http://www.koi.com.my/forum/KOI_Talk...filter_P26758/
which looks like something simmilar.

Read the article and I agree with only part of it. Yeah those worms
are a midge larvae who will most likely form a cocoon and then hatch
and fly away. He said in the article that it is bad news and that
your pond is muckey and needs a thourogh cleaning, not so I had a
fairly clean pond (bottom and all) freaked out when I saw the worms
and nuked it with P.P. --- anyway the worms came back in my filter box
in no time. Now they are gone but my gold fish are MUCH bigger and
hungrier. Certain flies lay their eggs on the water and they get
sucked into your filter where they hatch and prosper as worms untill
metamorphises time. I would worry if you see white worms hanging off
your fish which are anchor worms and nasty. Your worms will most
likely fly away or become tasty treats but you might have to
occasionly wipe away their tough cocoons they live behind. Crysilis or
somthing like that--- chow.