Feeding doesn’t get the attention it deserves. It gets a lot of attention, but it’s something that still feels like a self-evident part of reef keeping. As Rod Buehler, the man behind “Rod’s Food” put it, the old school of thought was “If it had a mouth, feed it.” Feeding fish is a no-brainer, since fish are always on the move and usually react with gusto at the sight of food. But feeding is so much more than making sure fish have something to eat, and today it’s so much more than feeding fish. Our reefs are miniature ecosystems and even beyond corals, tiny micro-organisms live and reproduce, aiding the ecosystem’s health, even though we can’t see them. Is it possible for aquarists to feed their entire tank, managing nutrition for a host of animals, including microorganisms they can’t see. To help answer that question I reached out to the creators of two leading frozen foods, Larry DuPont of LRS Reef Frenzy and Rod Buehler of Rod’s Food. 

The move to fresh:

Fish have eaten a lot of different things over the years. From flakes made of freeze dried fishmeal, on up to whole freeze dried krill. It was in the early 2000’s that New Life Spectrum (NLS) revolutionized prepared diets with their “one pellet” for every fish species methodology. NLS was created by Pablo Teapoot (I’m a little Teapoot short and stout, sorry couldn’t resist) a prominent fish breeder in the realm of African Cichlids. NLS used high quality ingredients, combining them with garlic and other natural enzymes to create a full bodied nutritional pellet for a variety of fish. NLS advertised their food as a hormone free alternative, which used natural color enhancers to create an immune system boosting diet. NLS eventually became popular in marine fishkeeping, and a variety of species accepted it well. It’s hard to forget Pablo Teapoot’s famous fish only aquarium, where Moorish idols and other finicky species thrived, eating only NLS pellets.

Yet for many marine aquarists NLS foods didn’t create the end all, be all of fish nutrition. Still today there are many species that simply won’t accept pelleted foods, and questions have arisen about how pellets effect water quality. There is also question about how natural it can be, moving an animal from a wild diet of naturally occurring fauna, over to a pellet prepared in a factory. It’s also hard to truly estimate how well corals and other invertebrates ingest pellets. It certainly is possible, but can a feeding tentacle really grab a quickly sinking pellet – even if that pellet is target fed. In my own personal experience I’ve found that pellets often slip off feeder tentacles, back onto the sand bed where they are gobbled up by a crab or fish.

Both Larry DuPont and Rod Buehler agree, fresh ingredients are key to a great marine fish food. Rod began using fresh ingredients in the mid-90’s after making the observation that human grade seafood must be superior to flakes or fishmeal based pellets. One of the great challenges in using human grade seafood, is that often freshly harvested seafood is rinsed in sodium tri-phosphate, which is a preservative. Sodium tri-phosphate (STP) is an inorganic compound, a sodium salt of the phosphate penta-anion. It actually forms the conjunction base of triphosphoric acid. STP is widespread in industrial applications, largely used in detergent. Environmental eutrophication (extreme algae blooms which are damaging to natural ecosystems) are attributed to the wide usage of STP. The last thing that any aquarist wants is a phosphate compound entering their reef, which is attributed to fueling massive algae blooms that wipe out aquatic ecosystems.

Fishes’ reaction to human grade seafood is obvious, but in the past it needed thoroughly rinsed to remove any STP preservative added. In the end, it’s hard for aquarists to feel comfortable at the thought of adding a phosphate compound to their aquarium, even if the food provided superior nutrition. This is where Larry DuPont of LRS Reef Frenzy found a breakthrough. From the companies’ headquarters in North Carolina, Larry is able to acquire freshly harvested seafood before it’s been rinsed in STP. The result is human grade frozen food that doesn’t need rinsed and is STP free. It’s a breakthrough for aquarists, as the food can actually be fed in its frozen state without the need for thawing or rinsing. It retains all the seafood’s natural benefits and can be strategically placed in various feeding apparatus, making it available for finicky eaters.

That isn’t where fresh ends:

Larry found that many foods spend months waiting to be distributed. It may seem to some like this isn’t a problem, there must be a way in the 21^st century to protect a food’s nutritional value without damaging water quality. What Larry found is that through a process called protein denaturation, proteins lose their tertiary structure due to the addition of salt, or stress such as heat or cold. This can cause the color or structure of foods to change, or worse the enzymes within foods to lose their activity. The concern is that many fish foods have preservatives added and go through a variety of stress before being packaged and shipped. Then they remain waiting for distribution, and go through stress once again when they enter the aquarium. The risk is that protein denaturation has so damaged the foods’ structure, that much of the original nutritional value is lost. To make matters worse, many frozen foods are shipped in a cooler with ice packs. Often when that cooler arrives at an aquarist’s door, the foods within are starting to thaw. They are then frozen again when the aquarists placed them in the freezer. All of this causes more stress, meaning more protein denaturation. To address this, Larry ships LRS foods with dry ice. Dry ice is capable of keeping the frozen foods totally frozen, so that after being flash frozen they don’t thaw out again during shipping. It removes an additional series of stress that can further denature proteins.

To work around protein denaturation LRS acquires fresh seafood within days of harvest, processes it into their retail mix and flash freezes it. This is done before the addition of any STP, meaning that LRS foods are STP free. Only a few days have passed between seafood swimming in the ocean, till it’s packaged and frozen. Since LRS self-distributes its own foods, aquarists are feeding it to their animals within 14 days of the seafood’s original harvest. Instead of sitting in a giant freezer at a distributors losing protein value, LRS food is moving quickly to get into your animals’ stomachs. Instead of multiple stressors before being processed into food and added to the tank, the food is only frozen once and thawed the moment it enters your tank, allowing the proteins and enzymes to maintain much of their function.

This mentality is much like the “farm to table” trend so popular today. If foods are harvested locally and the consumer is getting them fresh, they retain much of their nutritional value when compared to something frozen or prepared which has waited months to get to your table.

Feeding everything:

Not every successful reef aquarist feeds their corals and other invertebrates, and it’s still commonly accepted in the hobby that photosynthesis provides the bulk of nutrition for light hungry animals. Still, every coral species has specialized adaptations for eating foods available in their environment. I became a proponent of feeding a few years ago, after experimenting with it and having great results. Often the trick to feeding is having powerful filtration. The filtration must be shut off for a few hours while the corals consume food, but upon being restarted has to remove much of the food within the water column. Today there are a variety of coral foods on the market, primarily made of phytoplankton and zooplankton, but many coral species can eat full bodied mysis shrimp, black worms, etc.

What we have learned is that full blown reef aquariums have a host of inhabitants. From bristle worms to copepods, to nearly invisible micro-animals. All of them play an important ecological role within our aquarium. While many of these animals get their nutrition from naturally occuring algae or detritus within the tank, it’s possible for that to be exhausted over-time in a closed ecosystem. It’s a relatively new concept that one food can feed an entire reef aquarium. It started simply enough, with food blenders like Rod Buehler adding cyclopeeze to feed mixes. The hope is that the tiny cyclopeeze would disburse throughout the tank, making their way to some of system’s invisible inhabitants.

Larry DuPont at LRS took the approach of creating a nano-blend food. All the ingredients of other reef blends are shredded down to a tiny size, so that it’s easily digested by corals and other invertebrates. To try to reduce the strain on filtration, LRS balances their nano-food with coral foods in a pre-measured amount. The idea is to make sure there are small particles of nutritious food for animals that can consume them, but also microscopic foods for filter feeding animals – yet not so much that it overwhelms the tank’s filtration. The approach that LRS is going for, is that one food blend can feed everything in your reef, or mixing two blends together can serve as 360 degrees of feeding. Thus, it makes life easier for the aquarist as they don’t need to dose specific coral foods in addition to feeding their fish.

Good fat v. bad fat:

Docosahexaenoic acid (DHA) is an omega-3 fatty acid, a primary structural component of the human brain, cerebral cortex, skin, retina and yes, sperm and testicles. It’s widely considered good fat and can be obtained from fish oil, hence the popularity of fish oil supplements. Cold water fish are rich with DHA omega-3, and it’s believed they obtain it largely from microalgae which increases in availability as you travel up the food chain.

Eicosapentaenoic acid (EPA) is also an omega-3 fatty acid, and it was once believed to prevent heart attack or stroke, but studies have shown that it doesn’t. While fish contain EPA, they do not naturally produce it, obtaining it from macro-algae and other matter that makes its way around the food chain. EPA is often considered bad fat in captive fish, as it can accumulate as fatty tissue build-up behind the eyes and around the organs.

When feeding our aquarium fish, it’s vitally important to balance the good fat vs. the bad fat. Since both DHA and EPA are common in marine diets, it can be difficult to sort the good from the bad. Since captive fish get a fraction of the exercise their wild counter-parts do, their foods need to take that into consideration. To find out the fat profile of LRS foods, Larry DuPont invests in fatty acid profiles, which provide him the information needed to tailor LRS foods to aquarium fish.

That wonderful smell:

Those of us familiar with frozen fish foods notice the smell. If you’ve ever discarded a packet of frozen fish food and left it in the trash for a few days, I am sure your entire house noticed the smell. The first step to making a fish food effective, is getting the fish to eat it. Since we are often attempting to coax highly stressed fish into eating, there needs to be a powerful incentive. Shrimp brains are known to have a powerful smell, and beta-carotenes and black worms have an almost sweet, succulent smell. Since many fish species use smell to decipher what is food and what is not, blending these smells together to create a feeding response is critical.

Smell isn’t the only thing that entices fish to eat. The movement of food plays a large role, and many species won’t touch something that looks artificial, no matter how good it smells. This is another reason why in-tact, natural seafood is such a popular feeding option. In aquarium currents it looks alive, and thus entices fish to eat. Black worms are famous for enticing even the finickiest feeders to eat, due to their wiggling motion when placed in aquarium currents. LRS foods recently started adding black worms to their fish only diet, for this exact reason.

Unlocking the potential of feeding:

Since Larry DuPont started LRS foods, he has been contacted by members of the scientific community. It’s believed that his food aided in the health and care of difficult to keep species, and also helped entice various fish to spawn in captivity. With that, LRS has released a Fertility Frenzy diet, aimed at marine fish breeders, and providing enhanced nutrition specifically targeting spawning. It begs a larger question; are we just now unlocking the powers of feeding. Could nutrition, and access to fresh foods be a huge leap forward in our ability to not only keep, but spawn marine fish?

For so long our animals have eaten freeze dried flakes and highly refined pellets, food stuffs so battered by protein denaturation that they lost much of their original, natural benefit. Could a “farm to table” approach to feeding our aquariums bring about a renaissance in aquarium keeping and begin a new-age of captive breeding efforts. Only time will tell.