Julian Sprung Julian Sprung

Julian Sprung is an American writer on marine aquarium fishkeeping. He is an alumnus of the University of Florida where he studied zoology. Sprung has authored articles in aquarium hobby publications such as Freshwater And Marine Aquarium, Advanced Aquarist Online, Practical Fishkeeping, and Tropical Fish Hobbyist.

Sprung has authored or co-authored several of our favorite aquarium books, including Corals: A Quick Reference Guide, The Reef Aquarium series, and Algae: A Problem Solver Guide. With fellow marine aquarium enthusiast Daniel Ramirez, Sprung co-founded Two Little Fishies in 1991, a manufacturer of aquarium equipment, supplements, media, and more.


Tell us about your first aquarium. How old were you when you got it, what did you keep, and who or what inspired you to get involved with fish keeping in the first place?

Before I could actually have an aquarium at home I kept buckets with fish and small live rocks, starting when I was about 7 years old. I know, that must seem like strange image, right? We lived on a residential island on Biscayne Bay in Miami Beach, Florida. I could go to a vacant lot near our house and collect sargassum fish, sergeant majors, filefish, pipefish, shrimps, crabs, and other creatures. With a daily water change a balanced “aquarium” could be maintained in a bucket shaded by a tree. I'd change water when I got home from school (the seawater was right there), and they were good until the next day. Obviously, I had to take care not to put too many fish in a bucket. I could catch live mysis shrimp as food using a butterfly net.

Biscayne Bay, Florida Photo Credit: Atlantic Oceanographic and Meteorological Laboratory - NOAA Biscayne Bay, Florida Photo Credit: Atlantic Oceanographic and Meteorological Laboratory - NOAA

The first real aquarium I maintained was at my father's office when I was 10 years old. It was a 20-gallon fish-only tank. An undergravel filter with airlift circulated and filtered the water. It contained some saltwater killifish, blennies, Grey Angelfish, and other fish that I collected in Biscayne Bay. It even had for a year or so a rare yellow Brotulid I found during a very low tide. The Brotulid was out of water when I found it, and it gave birth to 8 babies when I put it in the bucket. I had some pretty amazing experiences collecting marine life along the shores of the island where I grew up.

I was introduced to the marine aquarium hobby by my brother Elliot, who showed me the aquariums he set up and maintained at a neighbor's house when I was just 4 years old, and he was 13 (in 1970). He also took me collecting around the island and at other productive areas like Miami's Rickenbacker causeway. Two years later our parents allowed Elliot to have aquariums in our home. There was this reasonable concern they had with saltwater and corrosion. My father said that salt spray from the tanks would escape and corrode things near the tank. He was right of course! That did not mean that he did not like aquariums. He loved them, but he also loved our house.

A visit to the Florida Marine Aquarium Society's annual show at Miami's Museum of Science in 1973 was also very influential in my fascination with this hobby, as it opened an ever-expanding universe of aquarium experiences for me. This was where I saw blue ribbon eels, clownfish, Royal Grammas, and hepatus tangs for the first time. It was like discovering a new Technicolor world!

I maintained several aquariums at home until I graduated from high school. I brought some of my aquarium pets (including corals) with me to college, and because of the need to be portable, I maintained them in a nano reef aquarium. So the need to be able to easily move my aquarium and maintain it on a low budget is part of the inspiration for my interest in promoting the idea of making reef aquariums work on a small scale.

You are a frequent speaker at aquarium shows and club meetings. Do you find that the material in your lectures holds up over time or are you constantly having to tweak presentations to take new discoveries into consideration?

I don't give the same lectures. I do have some lectures that I've given more than once, but I try to create a new topic each year. It's true that I share new discoveries in my lectures and it's also true that my ideas about techniques change over time as I learn from personal experience as well as the exchange of ideas with other hobbyists or professional aquarists.

You are probably bombarded with questions from hobbyists since you've been a figurehead in this industry for so long. What would you say are the top 3 questions you hear from people?

1. How do I get rid of red slime algae (or other problem algae)?
2. How do I get rid of Aiptasia?
3. Why can't I keep Acropora (or other corals) alive?

Julian Sprung book signing. Photo Credit: korallenriff.de Julian Sprung book signing. Photo Credit: korallenriff.de

You've written several of the aquarium hobby's most quintessential books, such as The Reef Aquarium: Science, Art, and Technology, and Algae: A Problem Solver Guide. Do you have any plans to distill these tomes of information into digital formats so they can be more easily consumed by today's younger hobbyists? Like maybe audiobooks or a video series, for example.

We did make a digital version of The Reef Aquarium volume 3 Science, Art, and Technology. It's available on the iBookstore on iTunes. Perhaps we will make it available in other formats as well.

Audiobooks? Can you imagine listening to me for hours going on about calcium and alkalinity? ZZzzzzz. Readers may not be aware that the first product of Two Little Fishies actually was a video titled "An Introduction to the Hobby of Reefkeeping." It's dated now of course, as it was produced in 1991, but it did surprisingly well at the time and helped launch our company. Sometimes I think about doing short videos of my own production, perhaps making a YouTube channel. Lately others have videotaped me and posted the videos on their channels. I have no plans at the moment for book work, though I do sometimes fantasize about creating new books. It was hard work creating the books we published, but also fun. I learned a lot doing them, and it was not just the writing… I was involved in the layout, color correction, proofreading, etc. as we were the publishers and producers of the books.

Julian Sprung Julian Sprung's home aquarium and display refugium. Photo Credit: Afishianado

What do you think about the recent rise in popularity of growing algae to control nutrients in the aquarium? It is not a new idea, but is it an idea that's time has come?

As you suggested, the interest in growing algae for controlling nutrients is something that has blossomed and then waned several times in the history of aquarium keeping. Early use of Caulerpa and even Chaetomorpha in filter chambers or tanks was known as algae filtration in the 1960s and 70s. The technique can be found in books and articles by Peter Wilkens, Stephen Spotte, and Frank Degraaf, among others. In the early 1980s to mid 1990s Walter Adey promoted algal turf filtration, which is a different sort of design that he patented, based on filamentous algae grown on screens, with water flow provided in pulsed waves, and frequent harvesting by scraping the screens. The algae are illuminated on a reverse daylight cycle compared to the display tank to balance the oxygen depletion at night and to stabilize the pH. Adey also grew algae in refugium aquariums connected to the display aquarium. In the late 1990s and early 2000s Leng Sy promoted growing Caulerpa in refugium aquariums containing Miracle Mud. His refugiums are illuminated 24 hours. Now the latest algae filters are Chaetomorpha reactors and vertical turf filters, each made feasible by the availability of low-cost, thin, high intensity LED light sources. To your question… what do I think? I like them… always have liked growing algae to filter the water. I like algae in “display” refugiums. Why hide it in the cabinet?

Who takes care of your aquarium(s) when you are away? Do you use a controller? What kind of automated systems do you have in place to help keep your tank parameters stable?

I have a couple of Apex controllers for two of my aquarium systems and the others have water top off managed by simple programmable timers. I've left my home aquariums unattended for nearly 3 weeks. Usually everything is fine when I return. OK, maybe a coral gets stung or falls but generally things look good despite the lack of attention. The controllers do help of course! At Two Little Fishies my staff do look after the aquariums when I'm away.

Two Little Fishies Phosban Reactor wins the Marine Depot Best of 2015 award for Best Media Reactor Two Little Fishies Phosban Reactor wins the Marine Depot Best of 2015 award for Best Media Reactor

What is Two Little Fishies best-selling product of all time? Which new products are you most excited about?

In May 2018 we were 27 years in business. By sheer numbers I think our SeaVeggies and the SeaVeggies Clips are number one. AquaStik is not far behind. Our sales volume of the Reef Aquarium Vol One was pretty significant at the time it was in print, when people still read books. There was a time when book sales generated more than half our annual income. Now they are less than 1% of our sales. That's a sad fact, not so much for Two Little Fishies because we adapt to the changes, it's sad for the aquarium hobby, and of course the world of publishing. But that's an old story already and not what you were asking. MarineSnow, AcroPower, PhosBan and the PhosBan Reactors are important too. I am of course most excited about our new synthetic seawater mix, AccuraSea1. It took a long time for me to develop and bring it to market, so in a way it's like a new baby, much the same way our books were a hard labor that produced a cherished child. I'm also excited about our new product STAX, the sliced natural porous limestone rocks that make aquascaping a snap.

What is the #1 mistake most hobbyists make? Not testing their water often enough? What are your thoughts on the recent wave of mail-in water testing services?

Hey, that one question is a threefer. I think the number one mistake that most hobbyists make is not quarantining fish. Fish get sick and die not because something is wrong with the water but because they carry parasites. When the fish get sick and die the hobbyist (or the dealer where he shops) automatically decide to test the water… it's comforting to find an “ahah!” reason for a disease outbreak, but the most likely reason is the lack of quarantine. Testing has a lot of utility, don't misunderstand me, but I think testing is too often used to make aquarists feel that they aren't caring for their aquarium enough, and that reinforces the belief that aquarium keeping is hard and complicated… that you have to balance all these things, blah, blah, blah. Too much work, right? Ask anyone who isn't an aquarist what they think of aquariums and it's sure thing they will repeat the same mantra like a reflex, as if the story is genetically encoded in non-aquarium keepers… “it's too difficult, you have to balance the water quality, it is time consuming, hard work, and it's expensive.” Do we as an industry really want to promote that narrative? Is it really true?

ATI Labs ICP Test Kit Mail-In Water Testing from ATI Labs

Now, about the mail-in water testing services there is a whole other purpose that they accomplish, if the test data can be taken as accurate. This new philosophy proposes to find individual elements that may be outside of the normal range (too low or too high) and recommends water change or supplement additions to bring the elements back to the target ranges. Does that promote the narrative of complexity? Probably, so it's not a beginners starting point. However, for the advanced hobbyist who may be interested in the detail offered by these services, it empowers an even higher level of control than previously possible… all with the caveat that the test results must be reasonably accurate for the concept to be of value.

What are some things aquarium hobbyists in the United States can learn from hobbyists in other countries?

I've travelled all over the world to meet aquarium hobbyists, and what's true is that they have so much more in common now compared to when I first began visiting other countries to meet aquarists. The internet has flattened the “aquarium culture” globally. You have more differences among hobbyists than between countries. Every country, aside from the USA, is convinced that they don't get the best marine life. They all have to deal with Aiptasia and cyanobacteria, among other pests.

What is the most you've ever paid for a fish or coral?

I don't know actually, maybe a few hundred dollars. The prices these days for some frags is breathtaking! I did, however, arrange the purchase of what is currently one of the most expensive marine fishes, when practically nobody had ever seen one… a peppermint angelfish (Centropyge boylei), in 1991. I got it from Richard Pyle. He mailed it to me!!!

Peppermint Angelfish Peppermint Angelfish

As background it is important to put this in context…in 1990 I passed through Hawaii and visited Bruce Carlson at the Waikiki aquarium on my way to Australia, where I was going to visit my brother Elliot, who lived in Sydney then. My timing was pretty good because Bruce told me that it would probably be worthwhile to visit Richard Pyle, as he had some unusual fishes in his aquarium that nobody had ever seen before. Imagine walking into a dark room with an aquarium illuminating several specimens of Centropyge boylei, Centropyge narcosis, and Belonoperca pylei. Richard and Chip Boyle had just collected them and all were new to science. That day felt like we'd all landed on an alien planet where they happened to have amazing reef fishes too.

Fast forward to 1991…at that time I was maintaining an aquarium for a wealthy hobbyist and I told him about this amazing angelfish Richard had discovered… nobody in the continental US had one of these fish. Well with that background story and the fact that Richard had a spare angelfish, it was not difficult to convince the parties to make it happen. These days I think Peppermints sell for about $15,000.

What do you do in your spare time? Catch a ball game? Go for a hike? Binge-watch your favorite shows on Netflix?

Spare time… let's see, what's that? Lately it is not something that I have much of. I try to make time for things I enjoy like cooking, gardening, canoeing. Yes I like hiking, but usually only have the opportunity to explore like that when I travel with my wife. We just returned from a trip to Utah and Arizona to visit national parks and I got my fill of hiking for the year. I have missed so much television that it's pathetic. It's not that I don't enjoy watching shows, I just never make the time to do it. I'm always writing or researching something, answering e-mail and technical questions, and dealing with daily demands of running Two Little Fishies. My wife sometimes watches shows on her phone… I know it's common, but I haven't gotten into that small screen viewing… definitely prefer a bigger screen. Watching my aquariums is something I do every day of course. My son recently got me hooked on Stranger Things… we did binge on that for a couple of days, but I'm already behind on the latest season.


? Watch our Q&A video series with Julian Sprung where we discuss topics like water testing, coral dipping, and biopellets.