You mentioned livestock choices. I’d appreciate it if you could go into a bit more detail on which ones you consider to be the “bad apples” when it comes to contributing to the likelihood of an ich or any other disease outbreak. Thanks. Could be fish, corals, anything.
I didn't mean it in the sense of "avoiding" certain species because of their predilection for ich; I don't think there are any species that are outright immune to ich if they are sufficiently stressed and I think that species/genus's that are more notorious for their susceptibility to ich can live in a tank with ich if husbandry is adequate.
For example; Currently, I have a powder brown tang who does not show any outward signs of ich. Previously, I lost wrasses and clown fish in my first encounter with ich.
What I meant was more along the lines of being a little conservative with the quantity of fish, the rate at which fish are added and known incompatibilities between species when confined together within an aquarium. Inattention to these will all stress the fish, compromising their immune system.
A lot of this is commonly discussed (No multiples of certain tang genus's, fish aggression levels, water parameters, feeding habits etc.). Here are some things that I have observed which I do not see discussed very much:
- I think fish take longer to "settle in" than might be thought. People seem to think a fish is settled once it stops cowering behind your rock-work, say a week. I think it can take a few weeks or more for the "pecking order" to be established and I don't think it's a good idea to add fish too quickly.
- I observed my fish fighting mostly over sleeping space. My original rock work was quite sparse. When I destroyed my rock work to catch all my fish to go fallow, I made a point of creating a lot more caves / retreats for the fish, even though it compromised my original "aesthetic". They all seem much happier with the new arrangement.
- I think within the first year, most tanks are just not stable. I know this is something almost no-one would consider, but I often think I would have saved myself a lot of heartache (and money! and trouble!) if I would have withheld stocking the tank for at least 6 months; Maybe just some clowns and a wrasse to keep things ticking over. There's so much going on in the first year and you have your hands in the tank so much, there's almost no way to avoid stressing the fish out. Almost everyone I know who has lost a lot of fish to ich has had their tank "in flux". People that have very mature, stable, reefs are able to add fish seemingly at will and can look forward to using their yellow tangs seniors card to buy cheap movie tickets in a few years. I guess if you are very experienced or are transplanting a lot of material from a stable system, this may not be an issue.