Still flashing, appear healthy

[Harlow]

I've got 15 tiger barbs in a 30 gallon tank with a handful of other fish. Only the barbs are flashing against structures. They've been doing this for over a week. I'm on my 5th day of treating the water with malachite green (or however you say). Flashing aside, they appear healthy. There's no visible disease on the fish's gills, I see no indication of velvet, no white spots suggesting ich, no laborous breathing, they are spreading their fins fully (clutching fins closely suggests some diseases) the fins appear fine. I'm stumped. I've lost entire tanks to disease before and it started with tiger barbs. Anyone have any suggestions of what to look for? Other possible diseases? Other possible treatment? I really dont feel like having this tank wiped out again. No other fish are behaving this way. Only the barbs.

 

[pip walters]

Parasites such as trichodina and chilodonella, which may cause the flashing, are quite resistant to malachite green. If there are no visible signs, then you could really do with a skin scrape looked at under a microscope.

You could try dipping the fish in a salt dip - 15 to 20 grams per litre - for up to 15 minutes. Remove the fish if they show signs of stress. This will kill chilodonella and may help kill or remove flukes.and trichodina.

Malachite is normally more effective when used with formaldehyde. Is malachite not banned in your part of the world due to its carcinogenic properties?

 

[Harlow]

Here in Indiana of the good ol USA, malachite green apparently in not banned. I bought this bottle of quick cure made by A.P. (aquarium products) at walmart for less than 3 bucks. it says for ick and protozoan parasites on it. active ingredients are formalin and malachite green.

I have no real good way to get a skin scrape looked at... especially not anyone who could tell me anything about what would be seen in it. suppose I were to do a salt dip. You mean take them out of their current aquarium and administer the salt dip in say a quarantine tank or something else? My point of asking is, if I treat them in some other environment, is it still necessary to treat the water of the tank they live in? The only parasite I've had to deal with to date is ich, and in that experience I learned it is necessary to treat the water, not so much treating the fish. Would i have to treat the water with some other treatment for the parasites you're speaking of?