Rich Ross

The future begins tomorrow

Skeptical Reefkeeping Part 1 – are you sure that that thing is true, or did someone just tell it to you?

 From Reefs Magazine

 “Are you sure that that thing is true, or did someone just tell it to you?” – They Might Be Giants

Is this the tank of your dreams? A healthy dose of skepticism might help you get there. Photo by Sanjay Joshi

Reefkeeping is as much an art as it is a science. There is so much that we don’t understand about what actually goes on inside our boxes of water that we must rely on cultivating a ‘saltwater thumb’ for success over time. Building that saltwater thumb, however, can be a daunting task. There are a million opinions on every aspect of reef keeping, and the modern reefkeeper can access those opinions thru websites, online forums, or those big heavy things on the shelves at home (Books? I think that’s what they’re called). Essentially, you can find support for every aspect of the hobby regardless of how ‘fringe’ it may be – the question is, how do you sift through all those opinions to make decisions about what to do with your reef tank? My answer – be a skeptic. In the next few issues of Reefs Magazine, we’ll look at critical and skeptical thinking, how they relate to reefkeeping, and how they can help you wade through the flood of good and bad information available to the modern reefkeeper.

Be a Skeptic

The idea of being a skeptic seems to have a negative connotation, as if somehow being skeptical means saying no for the sake of saying no. That’s not quite right. Skepticism is a method, not a position. Officially, it’s defined as “a method of intellectual caution and suspended judgment.” A skeptic is not closed minded to new ideas, but is cautious of ideas that are presented without much, or any, supporting evidence. In our hobby there are tons of ideas presented without much supporting evidence. Being a skeptical reefer essentially boils down to taking advice/products/new ideas with a bucket of salt, and following up to get a handle on why, how and if the suggested ideas actually work. This boils down to the one adage about reefkeeping that almost every experienced reefer agrees with, namely, be patient. Taking your time in your decision making is just as important as taking your time stocking your reef because, as they say, “nothing good happens quickly in a reef tank”. So, when that shiny new idea about reefkeeping shows up, with many people being very excited – slow down and think.

The series of tubes we call the internet is full of good and bad information. Make sure you filter everything well. Photo by Richard Ross

Why bother?

Two reasons – animals’ lives and money. The animals in our glass boxes rely on us to keep them alive, and if we embrace a methodology that turns out not to work, they die. Seems like a simple idea, but many people prefer to do what seems quick and easy, instead of being patient and thorough, and it does indeed, cost animals their lives. Need an example? Every year or two there seems to be some kind of salt controversy. Either X brand of salt is bad so you should stop using it, or X brand of salt is good so you should start using it. People rush to switch salts and some crash their tanks or kill their corals. Only then do they start looking into the reasoning behind the claims that got them to switch salts in the first place. And what do we usually find? Someone saying, “Things looked better.”

Do these colors come from magic potions or sound husbandry? Photo by Sanjay Joshi

As it turns out these animals cost money, sometimes lots of money. Killing them by embracing untested, unsupported methodology is throwing money away. Not to mention, that simply embracing the “new methodology” costs money in itself – salt, for instance, isn’t cheap. More importantly, we can’t ignore that the animals we keep are a finite resource and that we are ethically responsible for their well being.

In an effort to maximize the life and health of our reef animals, and spend money wisely, lets look at some methods for sifting through online information.

Anecdotal evidence

There is so much reefkeeping information available on the interwebs and so much access and participation in discussion by experienced reefers that our hobby has really jumped forward in leaps and bounds. At the same time there is much information out there that just doesn’t pan out, or have any actual support. Most of this is based on anecdote. Merriam-Webster defines anecdote as “a usually short narrative of an interesting, amusing, or biographical incident”. More hardcore, Ron Shimek says “Anecdote is unsubstantiated or unverified observation generally made by an unqualified observer who often really doesn’t know what they are looking at.”1 . For example, ‘I did a water change and my hair algae algae went away’. That’s a nice and harmless observation, but can a generalization be generated from it? Should you do a water change when you get hair algae? This is exactly where being skeptical comes into play. What kind of algae (there are many)? Was it actually algae or something else like dinoflaglates? What else was being done to get rid of it (usually lots of things)? What does ‘went away’ mean? Will it come back? What about all the cases of tanks with hair algae that didn’t go away after a water change? Unfortunately, anecdote is often converted to ‘Truth’ with amazing speed. “I did a water change and my hair algae went away’ gets converted to ‘water changes make hair algae go away’ which simply does not pan out across different reef systems. Even worse is when the observation isn’t all that harmless, as in the case of saltwater ich, Cryptocaryon irritans.

Real or a mirage of photoshop and macro photography? Photo by Sanjay Joshi

A case in point

Several years ago a thread was started on an online forum about a possible new cure for ich. Throughout the thread, many common fallacies were used that I think all reefkeepers should be aware of because poor reasoning leads to poor decisions. The original poster reported that they had ich on their fish for four or 5 days. They put ginger in the fish food and, hallelujah , the ich went away within 24 hours. Therefore ginger cured the ich. This is the most often seen fallacy, or logical misunderstanding, that we see in reefkeeping – post hoc, ergo propter hoc – Latin for “It happened after, so it was caused by”. Correlation is not causation. Just because one event occurred after another doesn’t mean the first event caused the second. A classic example would be that after a rooster crowed, the sun rose. Therefore the rooster’s crowing caused the sun to rise. Seems silly because we all know its silly, but it gets a little more complicated when we want to believe. Cryptocaryon has a complex and confusing lifecycle. To help explain why the posting claiming that ginger cured the fish of ich is fallacious lets take a quick look at the lifecycle:

The lifecycle of crypto is summed up well in an article in Reefkeeping Magazine, so I’ll quote Steven Pro: “The stage where the parasite is attached to a fish is called a trophont. The trophont will spend three to seven days (depending on temperature) feeding on the fish. After that, the trophont leaves the fish and becomes what is called a protomont. This protomont travels to the substrate and begins to crawl around for usually two to eight hours, but it could go for as long as eighteen hours after it leaves it’s fish host. Once the protomont attaches to a surface, it begins to encyst and is now called a tomont. Division inside the cyst into hundreds of daughter parasites, called tomites, begins shortly thereafter. This noninfectious stage can last anywhere from three to twenty-eight days. During this extended period, the parasite cyst is lying in wait for a host. After this period, the tomites hatch and begin swimming around, looking for a fish host. At this point, they are called theronts, and they must find a host within twenty-four hours or die. They prefer to seek out the skin and gill tissue, then transform into trophonts, and begin the process all over again (Colorni & Burgess, 1997).”2.

Some guy told a friend of mine these fish were reef safe. Photo by Sanjay Joshi

The short version of all that is that the trophonts, the actual white spots we see, leave the fish in 3 to 7 days without any treatment at all. This happens with or without ginger. It happens with our without many of the other crypto ‘cures’ I have seen tossed around including: water changes, salt mix changes, and my favorite, changing light bulbs! After this was pointed out, the original poster then did a bit of a turnaround and wrote that they weren’t sure that the ginger cured the ich and that more study would be needed. They did however stick to their guns regarding the ginger being a cure for ich. In my opinion it was critical for that information to have been included in the first post so people wouldn’t rush out and start feeding their sick fish ginger – which they did.

Soon, another fallacy reared its head, argumentum ad verecundium – an argument from authority. It was claimed that someone with a PhD in Europe previously developed this ginger method and it does “in fact” work. The idea here is that since a PhD said it, it must be true. PhD’s, or any authority, are wrong all the time about a great many things. There are few reasons to believe someone simply because they are an authority. In this particular case it’s even worse because no one could name the PhD, point us to anything that supported the claim that any such PhD existed, or that they developed a method of treating ich with ginger. Even once this was pointed out, the idea that the claim supported the ginger treatment idea persisted.

The original poster then picked up a fish infected with ich from the LFS to further ‘test’ the ginger method. It was presented that trying the ginger on another infected fish would give further credence that the ginger worked, but that was just post hoc, ergo propter hoc again but people ate it up claiming that the ‘scientific’ approach was wonderful. However, there really was no science – no control, no redundancy, no scrapes to determine levels of infection – it was all just anecdote! Some people ate it up, but some started asking questions.

One person pointed out that there was no science to support the ginger claim. They were immediately pounced on for belittling people just for trying something new. This is a form of the Poisoning the Well fallacy or trying to generate bias. The claim is that since the poster is belittling people, the points they are making don’t matter, but one has nothing at all to do with the other. The points really do matter. Even big hairy jerks are right some time. And, in this case, the poster wasn’t actually belittling anyone. People often take disagreement personally rather than talking it for what it was – pointing out that the proported conclusions about ginger don’t hold up.

Next, people said everyone should take a chance on a ginger treatment because it’s new and might work. This is an Appeal to Novelty; Just because something is new and shiny does not necessarily make it correct or worth trying. Sometimes new things are outright bad ideas – let’s use table salt for our reef tanks! There was also a little bit of an Appeal to Tradition, “Ginger has been used for centuries in Chinese medicine, so it must do something.” Just because something is done traditionally, doesn’t mean it actually has any effect – blood letting was also a tradition. Furthermore, the idea that something works on people, even if it were accurate, does not necessarily mean that it will work on other animals. We also got some observational selection. Some people posted that they treated their fish with ginger, but they died from the parasite. This claim was immediately swept away by people saying that nothing is 100%. You can’t dismiss results you don’t like just to make the claim you want to be true seem more plausible. There was also an appeal to ignorance. “Since there was no proof ginger didn’t cure ich, it could be concluded that it did cure ich.” Absence of evidence is not evidence of absence. Links to ginger being linked to antibacterial action were posted in defense of the claim that ginger cured ich. It was quickly pointed out that ich is not bacteria. No fallacy there, just your basic skeptical insight.

Ginger cures ick? Wow I didn’t know that, thanks. Photo by Sanjay Joshi

In the next 20 pages of the thread there was a lot of argumentum ad hominem, against anyone suggesting that ginger might not cure ich. Rather than, “We’re testing ginger, wait and see” responses became, “You just hate new ideas, so your points don’t matter” and “You think you are an expert, but you’re just a hobbyist like me so your points don’t mean anything” or, more to the point, “You’re stupid and ugly and I don’t like you.” Of course that makes little sense, loving or hating new ideas has nothing really to do with pointing out reasons there is no support for the idea.

For me, the important point was that the misinformation in the thread had been quickly converted to gospel. It started showing up on other forums as a proven cure. People started treating their fish with ginger. In the case of minor infections it wasn’t really a problem. Many fish are able to fight off minor infections. People with heavily infected fish that tried Ginger often ended up with dead fish when they could have used one of the proven methods to cure their fish of the parasite (hyposalinity or copper). This is the real world impact of non-skeptical thinking. Ideas get accepted as truth, when they aren’t. Luckily, the ginger treatment didn’t gain too much traction, even though it still gets brought up from time to time.

The Internet is a wonderful thing, but it can also be dangerous. You can find support for any idea, but your animals are counting on you. You owe it to them to make sure you aren’t just finding the answers you are looking for, but that you are looking for information with a critical eye.

One final thought about anecdote

Anecdotal evidence has its place in the world, and in a hobby like ours its downright necessary. defines anecdotal evidence as “non-scientific observations or studies, which do not provide proof but may assist research efforts.” Our hobby has certainly pushed research – just look at the lighting studies of Sanjay Joshi which helped to put to rest the misleading ‘watts per gallon’ lighting rule, or the recent skimmer studies by Ken Feldman that are putting some real data into what protein skimmers are actually doing. However, a lot of the stuff we deal with everyday has not really been looked at with scientific scrutiny because real science takes time, money, expertise and review. There are about a bagillion things that reefers want studied that simply aren’t going to be gotten to anytime soon. We all rely on observational reports to make some day-to-day decisions about our tank’s flow, lighting, feeds, animal interactions, and more. I think it is important that we remember that anecdote has its limits, be careful in your reporting and even more cautious in your reading.

Some reefkeeping products promise amazing things, so how do you tell the truth from bunk? More importantly, how do you write about bunk product claims without getting sued? We’ll find out in the next installment.

Links, further reading and references

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2- (

“The Demon Haunted World: Science as a Candle in the Dark” by Carl Sagan, 1997 (Ballantine Books)…dex.html#index

Rich is co host of the irreverent Reef Beef Podcast, the podcast that is like hanging out in the conference hotel lounge on Saturday night after the show has closed for the day. See and listen on youtube or any podcast source.

Skeptical Reefkeeping