I think it's about time I posted an update. I have some bad news, some good news, and a general strategy/progress report. So, let's get started...
First off, the bad news:
If you'll recall from earlier, the "chemical" side of my cleaning strategy was to be a high-concentration bleach soak, followed by Lysol, and then finished with isopropyl alcohol. I devised that plan according to the information from my vet and the articles I posted earlier. However, I've hit a bit of a snag in the plan. I was having trouble finding a Lysol product with the active ingredient those articles listed ("1% benzyl-4-chlorophenol/phenylphenol"), so I ended up contacting its manufacturer Reckitt Benckiser in order to find the item I needed. After a VERY frustrating series of back-and-forth emails and being directed in circles around the company of people unable or unwilling to put any effort into answering my question (seriously, is incompetency considered a marketable skill now?!), I finally got an answer: in order to unify their product line across all 50 states and their assorted safety regulations, they no longer manufacture any products with the ingredient we're looking for. So, dead end there.
The good news is that I may not need it after all. During my hours of research, I stumbled across this scholarly article:
Efficacy of Common Disinfectants against Mycobacterium marinum
in the Journal of Aquatic Animal Health.
The article is paid-access-only for non-subscribers, but I lucked-out in the sense that my brother is a university librarian and has access to it through their system. Based on what I learned reading it, I'm guessing that this article is the primary source used by the other articles I linked to earlier in describing what does and doesn't work against Myco
. As a result, there weren't many surprises in what I found, except for one fairly significant one:
work, even at less-than crazy concentrations.
There are some caveats however: namely that it requires much longer contact times (at least an hour) and, more importantly, this is not
a "real world" experiment, so we have to be careful what we try to apply to our tanks. What do I mean by that? These tests were done against pure laboratory samples of Myco
, not against those hiding in the biofilm that you'd find in your tank. I've heard concerns that such biofilm could serve as a protective shield keeping the bleach from ever coming into contact with the Myco
, which would explain the generally accepted belief that bleach is ineffective against it.
The article also said that 70% isopropyl alcohol required only a minute contact time to effectively kill Myco
(again, in a non-biofilm laboratory setting).
What does this mean for me and my cleaning protocol?
Obviously, Lysol is out. It wouldn't surprise me if the current formulation of it was effective, but at the same time I don't know that to be true, so I'm going to assume that it isn't and skip it altogether.
Here's my current step-by-step protocol for each tank:
1) Drain all water and remove EVERYTHING (decorations, equipment, substrate, etc)
2) Thoroughly scrub the tank with a "Dobie" non-scratch scrubbing pad (they're made by 3M and are amazing) in order to remove as much algae and biofilm as possible.
3) Soak the tank for 1-2 hours in a 1:9 bleach solution to start killing the Myco
and kill/break-down the remaining biofilm.
4) Drain about half of the bleach solution and re-scrub the entire tank again with the Dobie pad
5) Remove the rest of the bleach solution and rinse the tank with tap water
6) Set the tank out to dry for a couple of days
7) Spray the entire interior and exterior of the tank with a liberal amount of 70% isopropyl alcohol (with an extra focus on seams and frame edges) in a well-ventilated room and leave it to evaporate completely. I repeat this step at least three times to ensure that every surface has sufficient contact time for the alcohol.
8) Rinse the tank again to remove any potential residue from the alcohol (I don't think there is any, but it can't hurt to be sure).
I'm also applying adapted versions of the above process to the non-tank items that I intend to salvage. For example, I can't realistically scrub the gravel I'm saving from some of the smaller tanks, but instead I'm using much longer bleach contact times and actively stirring it during that soak in order to use the naturally-abrasive nature of the gravel to scrub for me. Also, instead of spraying the gravel with alcohol, I'll be placing it in a bucket and soaking it for an extended period of time instead (probably at least a half hour).
For the things I'm afraid to treat chemically (primarily the driftwood and maybe the lava rocks), I'll likely be using a 3+ hour bake at 450+ to heat-sterilize them. I'm still going back and forth on if that's how I want to proceed with those items, so for the moment I'm just setting them aside while I work on other steps of the project (I continue to welcome your input on this!)
I've decided to not attempt to save the plants. As much as I cringe at the idea of replacing all of them, I simply haven't been able to identify a way to ensure that they wouldn't just act as carriers for the disease. That said, however, I won't be discarding all of them right away. Contrary to my earlier plans, I've decided that the 20gal Permanent QT that will be housing my remaining fish will be a planted tank rather than a bare one, so I'll be using plants from the main tank to set up the QT (with a bleach-dip in the middle) instead of just trashing them all. The original plan was that if one of them got sick, I'd euthanize it and re-nuke that QT to minimize exposure for the others. Instead, the new plan is to still remove/euthanize the sick fish, but I'll rely on the UV unit in the tank and Diana Walstad's idea of "good bacteria out-competing Myco
" in a healthy tank. Will this plan increase the risk of the other QT fish getting infected? Yes, however I'm not so sure that that's a bad thing, since we're already assuming they're carriers and I do have to let them die eventually so I can sterilize that tank and finally be rid of this stuff.
So, where am I in this whole process?
Overall, I'd guess that I'm at about 30-35% of the total labor involved (not counting wait-times, like when I'm waiting for the QT to cycle before I move fish and teardown the 52gal). More specifically:
-One of the 10gal tanks and one of the 2.5gal tanks are done with Step 7 of the cleaning protocol.
-The 20gal is almost done with Step 7 (still need to do the final alcohol spray).
-The equipment/decorations/gravel from those tanks are all done with Step 6 and are being prepared for Step 7 (since these chemicals aren't all that cheap on this kind of scale, I'm trying to group things together to get as much mileage out of each bottle as possible)
-The planted 10gal that all those guppies came from is currently in the middle of Step 1 (teardown/basic cleaning).
-The final 2.5gal has not yet been touched. I'm trying to figure out what I did wrong with my dry-start method HC carpet that seems to be failing, so I wanted to give it some more time to "rebound" just to see what would happen before I tore it down.
-My new-and-improved emersed-growth rig is now up and running (using both a larger container and a hybrid of artificial and natural light). I never tore down the original one that I was using to grow HC to start the big tank, so I have some HC, narrow-leaf Ludwigia, and some rather-expensive 'Red' Ludwigia that have never been exposed to the Myco
that I can grow out for when I get to the point of restarting my tanks. It's only been set up for about a week, so it's still too early to tell if my hybrid-lighting plan will work. I'd eventually like to shed the artificial light altogether, but I'd like to get it established before I try that.
-I've purchased a larger UV sterilizer of Craigslist to use on the 20gal Permanent QT (the 18w Turbo Twist model), but it's coming from a salt tank and has extensive mineral deposits that I need to clean before I can put it into service.
-I'm not going to do any teardown of the main 52gal until I get the 20gal Permanent QT up and running, so I've done nothing with that so far. The fish inside it are all healthy with extremely strong coloration, so I don't think any of them have active Myco
infections at the moment.
Sorry this got so lengthy! I realized it'd been a long time since I did a larger-scale strategy update, so I wanted to be thorough (especially for those who are in this same situation). As always, I welcome any comments/questions/advice you have!