Mebbid
Aquarium Advice Addict
Sorry, not trying to be nit picky but "good" is a very subjective term and everyone has their own definition. Im just trying to be thorough what exactly are the readings for ammonia, nitrite, and nitrate?
About the fish with ich -
The tank is contaminated with ich the moment you add that fish. It is almost 100% certain that there were also ich parasites that are in the free-swimming stage introduced, if only in the bit of water clinging to that fish.
So you could euthanise the fish if you wanted to (please don't just flush it, read up on using oil of cloves or boiling water) but that won't do anything to protect your other fish from ich.
Boiling water is far less humane than alcohol, ICE water (for tropical fish), our even clubbing and decapitation for that matter.
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