The other way of thinking is that this could be a dangeros form of red algae be sure to wear protective gear when working with it but our first thoughts would be the same as l.w. and Maggie that this red tinge comes from iron oxide perhaps it would be an idea to get a sample of water tested by your local water authority .
@Dave 54 @fishin4cars Help with anchor worms requested -- see previous post...
As for your anchor worm problem your going to have a bit of an uphil struggle with these and may I suggest if you recently bought new fish it came in wiith them .
Its latin name is for future reference "Lernea", I take it they must have reached the adult stage of their life cycle because when in a younger form Anchor worm infestation can be mistaken for other other parasite infestaions such as whitespot as they appear as white dots on the body of your koi/goldfish "dont know which as you dont specifically say which", but mistakes can be made all the same.
Do you know how to take scrapes and do have a microscope to hand for future use, if not it may be an idea on learning how to do so as ourselves and others do on this site :-
https://www.gardenpondforum.com/threads/microscopes-and-scrapes.11108/
A fish that has anchorworm will swim somewhat erratically even rubbing and flicking to try and re;ieve its irritation and dislodge the anchor worm parasite so you would have notied lots of that going on .
A word of warning here as these infestations can reach dangerusly high levels which if left untreated will threaten the lives of your fish (I remember seeing a photo of a goldfish that had over a hundered anchorworm attached to its sides head gills underside .
To treat anchorworm you must first physically by hand remove them from your fish,you can get a product callled oil of cloves from your local health food store and use this to anethatize your fish so that you can handle them:-
https://www.gardenpondforum.com/threads/anethatizing-you-koi-goldfish-the-various-stages-of.10493/
Why because your going to need to, as the problem your going to have is that the "wound site's" where the anchorworm was attached before you removed them can and must probably will become infected with a bacterial infection.So we recomend when you remove them to dab the resulting wound with Machite Green then to finish spray it with another product that can be bought from the same store as your oil of cloves called Propolis.
Propolis is a bye product of bees and is what bees use in their hives to disinfect the hive , and is something we have been using on our own koi for 22 or more years now.
Now we have to turn our attention to the free swimming stages of the Lernaea parasite and rid the pond of them.
To do this your going to have to treat the pond on a number of occasions because they will also have laid eggs , so you could say you have to kill junior and the babies as they are the future of the parasite .
To do this you will need to buy dimlin powder (which is banned in the UK) and treat as recomended.
We hope this helps you with your problem ?
Dave
