[Paul B]

It has always interested me why some tanks are plagued with ich and others seem immune. Most of us know all about the Ich life cycle but I believe we are missing something. Many of us have tanks where we know ich is happily living but causing no harm while other tanks just can't seem to keep anything alive. I know when my tank was new I was one of those people who had to keep copper in there continousely. Now my fish, including so called "Ich Magnet" hippo tangs are immune. My theory is that very healthy fish in breeding condition rarely get ich although I don't know why. Ich is a paracite and not a "real" disease. It is not internal, not a bacteria or virus so our fishes immune systems should not be able to launch a defense. but somehow it does. To me it seems it would be like being immune from gun shots.
I know there are theories about an immunity or partial immunity but I really don't see how that is possable.
I know that either my tank conditions or "immunity" if you will repels ich infections but I also know that ich is alive and doing well in my tank.
I have many times introduced fish with ich into my tank and the fish will either die or get cured but never will it affect other fish. I wrote about this before and I bring it up again because last week I bought a Shark Nosed Gobi, that seemed healthy so introduced it into my tank. I do not quarantine and have not in many years (my tank is wierd so you should always quarantine)
After a few days I noticed that gobi was full of ich to the point that I knew it would be dead in the morning. I caught it and cured it with copper in another tank. None of the other fish have ich and I know from experience that they will not get it. The other six or so shark nosed gobies in the LFS from the same shipment died in the store.
Does this happen to anyone else? I personally thing it is either a tank condition or a general health factor.
Anyway it is something that I think about and it bothers me that I don't yet know the answer.
Take care.
Paul

[ShaunW]

What you describe has happened to me.

My fish are all older than 5 years, some are 10 years old. In the beginning I did have ich, but I didn't do anything for it. The infection resolved itself, it did come back sometimes in the beginning, but now I have not seen any ich in my tank for at least 5 years.

I think people over react to ich infections. The treatments are sometimes worst than the disease. Also some individual fish are just more susceptible genetically IMO.

I do agree with your "breeding condition" theory. Mature fish are much more resistant to many stresses.

[juan319]

Paul, even thought I am new to saltwater, I read one of your articles on black worms, after that moment I read all of your articles. Your articles are very educational and informative.
The same thing (ick) happend to me after purchasing two fishes, my entire tank got contaminated. As of right now I am starting again to buy and add fishes to the tank, and I try to feed them black worms on a regular basis.

[Sean]

From my experience Ive also noticed that at wholesalers and such they just get a "bad shipment". I've alway assumed it had to do with the way they were caught and/or shipped. I've seen it with everything from damsels to hippo tangs. A stress, weak and starved fish as we know are more susceptible to having "ick". It kind of makes sense, at least to me. Who knows if it's fact but it's what I assume.

[Sean]

As a note being friends with some wholesalers I know they give "deals", discounts and lot pricing on these fish just to get rid of them before they die.

[NYreefNoob]

my clowns i have had for a few months now have had ich from the start of going into my tank.{still have out breaks of it} i do feed regularly with garlic. and thank goodness for my 2 cleaner shrimp. none of my other fish ever got it. knock on wood. i think keeping them feed and healthy will fight it off more than anything. seen guys lower salinity and have ich back a few months later. dont think there is a cure forever on it just a temp fix.

[JLAudio]

Paul, I have also noticed this in my past reef tank. Originally I never used a qt and only started after a goldrim got real bad ich. I knew there was ich present in by tank because new tangs that were QT'd 6 weeks would be introduced and get ich from my tank indicating ich present in tank, but yet somehow all the fish in my tank for years tangs including hippo's, yellow tangs, dwarf angels never ever showed a spot. Could there be an immunity?

[Bikinisalt]

I think when there is an ick outbreak in someones tank, people tend to panic and start putting stuff in there tanks that they should not be doing. I used to do it. I think I have killed off more fish trying to do the copper thing, add treatments, do the hypo salinity thing. Now if I get a ick outbreak on one or two fish and all the others are okay, eating, swiming around and have there colors, I leave things alone, raise the temp to 90 or even 95 and within a few days all is okay.

One other thing I want to add is; Most people that have a QT tank are either to small or not biologically stable and this IMO will not work. It is just going to create stress on the fish and eventually lead to problems. When I get a new fish, I do QT the fish in a 55G tank that is almost set up like a display, fully running with a few pieces of LR, LS, wet/dry and skimmer. This tank runs 24/7 fish or not. Once I feel the fish is okay then I put it in a tank that is running off the main display tank that has no fish in it so the fish can get use to the water conditions without it getting attacked by other fish. I do this because I like large angels and I know that the possibilty of them fighting and becoming stressed out can lead to a ick outbreak.

Can fish get immuned as they get older? IMO, Yes they can.Do I think ick lives in a tank even if the fish are not infected? IMO, Yes I do, I feel as long as there is LR and LS we will always have ick in our tanks. When I disturb something like moving some rocks around or a major water change, there have been times that I wake up the next morning and my Hippo tangs are covered with ick and my Salifin Tang has little black spots, but all my other fish are okay and once I increased the water temp, it goes away in a few.

[JasonE]

I equate Ick to fleas on a dog. A healthy and happy fish will have no problem, its only stressed and unhealthy fish that get it. Actually I think that applies to corals as well. I think acros can easily handle red bugs and AEFW if they are healthy, but succumb if they are not.
And I agree, that new tanks often get ick, if the system is not "cured" the fish will be stressed....
Personally, I'm not a fan of QT. I think it stresses fish out waaay to much.

[pecan2phat]

I've always felt that it is the secondary bacterial infection that digs the knife all the way in.