Think Tank

By Melaina Juntti

For dinner you choose wild-caught salmon and free-range chicken over the farmed and penned varieties, but when it comes to building a saltwater reef tank, sourcing from native environments is not the eco way to go. Although “reef-caught” may sound more eco-savvy than “farm-raised” or “captive-bred,” taking coral, fish, and flora from the deep-blue spells big trouble for underwater ecosystems—and your tank. Since reefs have endless nooks and crannies for coral-dwelling fish to hide in, captors use cyanide to sedate and source them, which in turn poisons the reef, explains Robert Hermanson, a biologist at the University of Colorado. Then, once caught and transplanted, the poisoned fish don’t just magically perk up and settle happily into their new 40-gallon home—they’re prone to disease and often don’t survive the traumatic move. Same story for plants and coral stripped from native reefs.

But you don’t have to forgo the pleasure these silky swimmers, rippling marine plants, and vibrant invertebrates bring to your home. Hermanson offers a few earth- and species-friendly tips for building your best tank.

Always choose tank-raised fish over reef-caught varieties. Why? In native habitats, fish expend tons of energy foraging, defending territory, attracting mates, and escaping predators. Toss them into a tiny tank, and they go, well, crazy. They also can introduce pathogens and disease from the wild into your tank. Tank-reared fish, on the other hand, only know life in captivity, and their immune systems are prepped for aquarium biotopes, meaning longer, healthier lives. Clown fish, sea horses, gobies, angelfish, and dottybacks are great breeds to try, but always ask your trusted aquarium shop employees about compatibility with other fish and coral.

Aquacultured coral, which has been fragmented from a captive-bred mother colony, is more colorful, disease-resistant, and faster growing than reef-cut varieties. Plus, you can easily re-propagate it and move pieces to other tanks—assuming your new hobby takes off. Great varieties include acropora, zooanthid polyps, waving hand xenia, and ricordea.

More visually appealing than waxy faux flora, live plants help oxygenate tank water and even supply fish with better-balanced diets. But hungry swimmers sometimes chomp entire plants within days, so you may have to test a few types in your tank. Halimeda and Maiden’s Hair plants usually thrive with fish, while lending diverse shapes and textures to your tank.

Forget chemical cleaners—snails, hermit crabs, and catfish scour interior glass and control nuisance algae that otherwise hogs growing space and light other organisms need.

Farm-raised live rock acts as your reef tank’s sewage-treatment plant. The bacteria that encrusts the rock and grows within it filters nitrogenous waste left by fish, snails, and shrimp and detoxifies the environment.