What is "Ich"? 2 Weeks, 3 Days ago
What is Ich? There have been a number of posts by new folks (or at least new to me) about it, so I thought I would throw this out there. Hope it helps answer alot of questions and gives some direction where to go if it apples to you.
Ich is short for Ichthyophthirius multifilis….a freshwater protozoan parasite. When we refer to “ich” in a marine environment, we do so because when people made the move to keeping marine aquariums from freshwater aquariums, they brought the term for the white spot disease with them. Actually, “ich”, or white spot disease in a marine system is either Cryptocaryon irritans (aka crypt) or Amyloodinium oceallatum (aka velvet)……with crypt being the most pervasive and most common seen. Both are protozoans and both have definitive lifecycles. Understanding these lifecycles is paramount in treatment and prevention. Velvet is not seen as often, because it has such a high and fast kill rate that most fish do not make it to the LFS, or at least on to the customer to be seen. Crypt will kill your fish too. It just does so in a slower, methodical and, to some, mysterious manner. The lifecycles of both parasites are very similar so I will just describe the lifecycle of crypt. Treatment for both is the same.
Crypt usually is introduced to your tank on a new fish. It can come in on coral or liverock from an infected system, but that is the minority case most of the time. But, for technicality here, anything wet can carry crypt into your tank if it came from an infected system. The parasite at this stage, attached to the fish, is called a theront. As a theront, the parasite grows from microscopic to the white spot you are able to see…..this is a temperature dependent process but usually occurs over a 3-5 day period in our tanks. Once the theront has grown to sufficient size and matured, it leaves the fish and falls to the substrate (usually in the dawn or dusk timeframe). At this stage it is a protomont. The protomont seeks out some calcareous spot to latch on by crawling around, but usually picks out a spot right near where it dropped off. In this manner, a fish will likely be very close by when the new parasites emerge. Once it latches on, it is in the tomont stage where it encysts, undergoes binary fission into 150-250 new parasites. Once ready (usually about a week or less) the cysts ruptures (usually in the dawn or dusk timeframe when fish are settled down and back in their borrows) and releases all the new parasites….known as tomites in this stage. Here they seek out a fish….and only a fish….to become theronts and start the whole thing over again. The tomite have about 18 hours to find a host fish….and only a fish….or they die. To reiterate, this is a temperature dependent process. There have been several studies done on this process….thanks to the mariculture industry….and after compiling all the results…which slightly differed….it is safe to say that the process has a range of 10-21 days in most cases. I always recommend elevating the tank temp to 80F and allowing a month for the lifecycle.
Treatments……well there are many put out there but only a few are really worth talking about. I have tried nearly all of them. I will only discuss the methods proven to work by a preponderance of evidence. I don’t count some guy’s brother’s cousin’s, friend’s roommate as evidence. That is what we correctly refer to as an anecdote…and most anecdotes rarely work against this formidable foe.
Best treatment…also called the “gold standard” for treating “ich” is ionic copper in a bare bottom tank with small sections of pvc pipes (for fish cover) for 14 days at 80 F. It is paramount that the copper be ionic and that it be at a therapeutic level (varies by brand, but I like 0.3 ppm for most) for a full 14 days. You will need to test to make sure you have not overdone or underdone it. This can be hard for some species….and yep, you guessed it, and the fish most susceptible to the parasite are also the fish most sensitive to the copper. That is why I like the dose I listed. Of course, it should go without saying that you cannot have any non-fish livestock in this treatment.
Hyposalinity…..I have used this with success, but you have to do it for at least 6 weeks, I feel. Every time I shortened it, it did not work and the fish reinfected in the following 2 week period. It is not as certain as copper, but is an alternative for those unfamiliar or averse to using copper. Again, 80 F and lower the salinity to 1.009. You will need a refractometer and again, no non-fish livestock. Also, puffers, eels and sharks/rays do not do particularly well with hyposalinity.
All the other treatments are of little value, but some get lucky and have fish that are healthy enough that the “reef-safe” treatment helped balanced the war in the fish’s side. Usually though, I just see a few spots here and there with no major outbreaks, but add a new fish and the whole balance goes back to the parasite and most or all of the fish in the tank die. Nutrition can help a fish fight off the parasite’s virulence, but at you can see from the lifecycle….only one parasite needs to make it thru to keep it all going. The systems that have crypt hanging out and “appear” to be gone, are really just ticking timebombs. A major parameter shift, like temp drop or pH swing and the infestations pick back up again. These are the folks that think temp or doing a big water change causes “ich”.
Most of the so-called “reef safe” meds are largely crap. Hate to be so blunt about it, but they just postpone the inevitable and, I think, are just cruel to the fish. People who report a “cure” with these things have really just beat the odds. I did try Paraguard in combination with hyposalinity and had great results, but I cannot say whether the hypo or the Paraguard did the trick or whether it was the combo. That powder blue tang is alive and well today in a totally crypt free system. Even when the temp in the tank dropped to 64 F last winter (power outage on my street and only had the watts to run the circ pump), nobody broke out. If they ever were gonna…that would have done it. I have also given, Chem Marin’s Stop Parasite, Kick-Ich, garlic, ginger and dips a try. None have ever given a cure. I offer my “anecdotes” for background, nothing more, but most of the authorities in the hobby will give you the same advice (or close) as what I am putting forth to you now. As a sidenote, I always soaked my foods in garlic guard and vitachem as a matter of nutrition and my fish love it. Don’t know if that has been a significant contributing factor, but my fish are always healthy and disease free.
Ok, those are my thoughts. And I did all that without referencing anything……just what I remember. If someone finds an error with the intel, please let me know.
The real issue here is that crypt in your display can be a totally avoidable occurrence..…….with a QUARANTINE tank. Those who know me knew I would not get out of here without mentioning that. Quarantine is one of the most important things that people DO NOT do with the regularity that they should. The only excuse I can ever see for not quarantining your livestock is that you want to have the headaches of parasites in your display. A QT tank can be as simple as a 20 gallon long tank with a HOB filter, a heater, a simple, single tube light and some plastic (PVC cuttings) decorations. You should QT all fish for at least 3 weeks and if they show no ill effects worth treating, then they can join the display. And if, Heaven forbid, they break out with something, you are ready to treat without risking all your pets’ lives.
I hope this helps someone. Even if all it does is convince a few folks to QT their fish, it will be worth the time I just spent typing this all out.