As a matter of time and of keeping your local pet shop going, look there anyway. They may have a comparable med. under a different brand name.

A while back I went looking for Triple Sulfa Plus by Aquatronics, only to discover that Aquatronics was no more. I was surprised by another company that carried virtually the same thing. That was also true when I got "stuck" with the big box store. When I mentioned Metronidazole to the kid who greeted me, his eyes drifted out of focus, and he replied that they didn't have that product. So I thanked him, waited for him to stagger away, took off my glasses (is there a tendency for livebearer and killinuts to be near-sided, goldfish, koi and cichlid nuts to be far-sided?) and squinted at the back of packages until I found my med.

Maybe I shouldn't have mentioned that, "I need some Metronidazole or Dimetronidazole to treat a fast moving. prolific flagellate in the Hexamida - Spironucleus group that are wrecking havoc in my lyretails' digestive system." Better to say, "My fish are wasting away and have hollow bellies.";)

Also, now that you have identified your beastie, check with goldfish and/or koi sites, as it is more common among pond fish. You may have to scale their treatment to your aquarium. :)

I wonder about pulling the worms off. I think that may be done with much bigger fish.

I would treat the tank. As you probably know by now, they are a parasitic copepod (a kind of crustacean) which look like a worm. There is a stage in their development where they attach themselves to a fish's gills (which we wouldn't see). Later, the larger adult females attach themselves elsewhere on the fish. (The males are off in a bar somewhere watching football.)

There seem to be several treatments such as the very toxic Dylox (dangerous to inverts - exit snails - and fish in overdose) some of them organophosphates. Dylox (and Dyacide) turns out to also be in a number of anti-parasite meds, so follow instructions! Even if the fish seem ok, there is (Fairfield again) the chance of long term damage liver and kidney damage (and your fish shows dropsey-like symptoms six months later and there is not a darn thing you can do about it.)

Fairfield mentions a newer med called Dimillin, trade name Anchors Away. :) It's nice to find a fish med company with a sense of the language.

He feels that is safer. Your Net search may come up with other useful treatments. Please mention them, as I would guess your thread here will become our Anchor Worm "Immediate Help" entry. :)

As far as post treatment for secondary treatment goes, your fish sound pretty lively. I would gravel vac a day or two after treatment, to get rid of mulm and dead Anchor worms and larvae. I would put a teaspoon of salt in each gallon of water you put into the tank with that water change. Later I would still rotate out the salt with non-salted water changes.

If you wanted to put the treated fish in a recovery tank with gravel, a plastic plant and airstone, that might be the place to does them with a broad spectrum antibiotic as a defense against bacterial attacks on the wounds. Putting the antibiotic in that tank leaves the nitrogen cycle functional in your regular tanks. On the other hand, you mentioned that they were in ALL three of your aquariums, so that probably wouldn't work either... unless you get a 55-gallon tank and dump everybody in there for recovery. ;)

If you get the 55, tell your family that was your idea and yours alone. ;)

Oh! Equipment (nets. siphon tubes...) might be left in the treatment tank or really militantly rinsed under hot water and left outside under the sun for a couple of days. Or I would toss the tubes in the bleach barrel - not the nets!

Once again, these wee beasties point out the need for a 3-4 week quarantine tank. I'll bet no one ever sees those larvae hanging on to the fish's gills. It is only later when they morph into adult external parasites that we see them.

Like you, I'm a little puzzled about how they got into your tanks. It may be that a LFS used nets in both feeder goldfish and regular aquariums. If they have a tank to tank, circulation system, that makes the possibility even more likely that the infection was from a shop.

If you harvest live foods from a place where there are wild fish or your fish spent a time in a pond, that also might be an entry point for the anchorworms. It is interesting and possibly important to find out where they came from. First though, treat those suckers!

You have three aquariums. If you have them on over and under stands, what a wonderful situation! You have room for a tank, which can be a quarantine tank! If there have been no new fish for a long time and you have an outbreak of a disease, it could become a treatment/ recovery tank.

Of course that is, if you haven't filled it up with baby guppies. ;)

Congratulations for hunting down the culprits! Good luck with the treatments!