Hi all. Need a little help again with this one please. For the past few weeks my fish have been acting strange clamping up on the bottom and flashing. One small koi looks like its the start of droopys but instead of eyes sticking out they look sunken in? And one looks like it's starting to get fin rot.
I get these strange problems around this time every year, water tested by myself and also took a sample for testing which is 0 ammonia and 0 nitrite. I even rang my water supplier a few years ago to ask if they put anything in the water around this time of year which they said they don't...
I did scraps a few weeks ago found nothing and done some more today and found 3 of these worm looking things and 5 dead ones, no idea what they are I've never seen anything like them before.... (Link for the parasite video https://youtu.be/hQhrJf_x50A)
My pond is 15 years old and for the past 5 years or so it's had a little leak so it's always on a auto top up through a 3 Stage filter, since taking the cover off after winter I can see the leak must of got worse so now around 40% of the water is replaced every week through the 3 Stage filter which had replaced filters about a month ago. I've brought a new liner but didn't want to stress the fish anymore by moving them around to replace the liner...