Create a Pico Paradise - How To Stock A Tiny Tank

Categories: Livestock, Saltwater

Last updated: Aug 22, 2024

Photo Credit: Tigahboy.h2o on Instagram

If you consider the very manageable physical size and minimal investment costs, it's pretty easy to understand why a pico tank is attractive. Small tanks don't cost as much as big tanks and you can put a pico just about anywhere. They make great additions to a bedroom, office, dorm room, kitchen counter, bookshelf, or just about any place the tank will fit. Maintenance is also very easy because the small water volume can be managed with a household pitcher and a short piece of airline tubing as a siphon.

Something that few folks consider is the fact that a tiny tank fills up fast and allows you to highlight some of the lesser-appreciated and more timid aquatic animals that would otherwise go unnoticed in larger aquariums.

Just a handful of coral frags will grow and fill the entire aquascape of a pico aquarium within 6 months. Since you can only stock the tank with a single fish or small invertebrates, something like a tiny clown goby or sexy shrimp can steal the show. These animals won't have to worry about competition for food and you just might be able to observe these animals more often because they won't be dealing with aggression from tankmates.

We are not making lemonade with lemons here and you should not forget that Pico tanks do pose a challenge. The success of these small tanks lands squarely on your diligence to perform regular water changes and missing even just a single maintenance task can send these tiny tanks spiralling. Choosing suitable livestock that can thrive in such conditions is equally important for your success which brings us to the focus of this article, how to stock your pico aquarium for long term success.

Photo & Tank Credit: Hello Reef

Photo & Tank Credit: PNW Customs

Pico-Sized Saltwater Aquarium

Volume: Usually less than 5 gallons (approximately 19 liters).
Characteristics: Pico aquariums are the smallest category of saltwater tanks. They require careful attention to water parameters and stocking due to their limited water volume. Maintenance tasks such as water changes and monitoring salinity and temperature are critical because fluctuations can happen quickly in such a small environment.

Nano-Sized Saltwater Aquarium

Volume: Typically between 5 to 30 gallons (approximately 19 to 114 liters).
Characteristics: Nano aquariums are larger than pico tanks but still considered small. They offer a bit more stability in terms of water parameters compared to pico tanks, but they still require diligent care. Nano tanks can also house a wider variety of marine life, including small fish, corals, and invertebrates, making them popular for hobbyists who want a compact yet diverse saltwater setup.

Pico Aquariums Photo & Tank Credit: PNW Customs

Our Top 5 Pico Livestock Picks

Choosing livestock for a pico can be challenging because 99% of the saltwater aquarium fish and other animals available are not suited for picos. So how do you make an impressive pico tank that captures the natural beauty of the ocean?

Choose a theme and stick with it.

Don't overstock the tank and choose animals that you find interesting and unique. Remember, the pico is for underdogs and allows you to spotlight things like snails, crabs, shrimp, and small timid fish. You won't be able to take a monthly trip to the local fish store to choose a new fish or coral but on the flip side, your pico tank will grow into an impressive display in no time and allow you to observe behavior that may not be possible in larger aquariums.

Pistol Shrimp with Watchman Goby Photo Credit: "Prater" in Vienna by Andreas Hurni is licensed under CC BY-SA 2.0.

1. A Match Made In Heaven

Pistol shrimp and watchman gobies maintain a natural symbiotic relationship in which they share a burrow. The shrimp builds the burrow and provides a home for the goby while the goby helps protect the shrimp from predators. There really is nothing cooler than to see this mutualism inside your aquarium.

I would only suggest these guys in larger pico tanks, closer to the 5-gallon size because they do need a few inches of substrate to burrow. You can find them sold in pairs which gives you the best chance of the two animals pairing up inside your tank. Without aggression from other fish, you will be able to closely observe their unique dynamic. When these pals aren't jetting out of the burrow to eat, the shrimp spends its time carefully manicuring the burrow while the goby anxiously stands guard at the burrow entrance.

Pico Reef Photo & Tank Credit: PNW Customs

2. Gobies, Gobies, Gobies

Small gobies are one of the few fish that can thrive in a pico ranging in size from 3 - 5 gallons. Just be sure to choose one of the smaller species that won't grow beyond just a few inches and here are some of the most common:

Clown Goby
Two Spot Goby
Starry Goby
Neon Goby - You can probably stock 2-3 of these!
Court Jester Goby
Link's Goby
Skilletfish

Sexy Shrimp

3. Alien-Inverts

One of the coolest pico themes is choosing to highlight some of the more unique-looking snails, crabs, and shrimp. In a large display tank, small invertebrates are often lost alongside the brilliance of tropical fish and corals. In a pico tank, you have a chance to shine a light on some of the most unique animals in the ocean. For the most part, these inverts can be housed alongside corals and even a small Neon or Clown Goby.

Pico Shrimp:

Sexy Shrimp
Peppermint Shrimp
Anemone Shrimp
Pistol Shrimp

Pico Crabs

Emerald Crab
Pom Pom Crab
Porcelain Crab
Decorator Crab
Halloween Hermit Crab
Scarlet Hermit Crab

Pico Aquarium
Photo & Tank Credit: PNW Customs

4. Teeny Tiny Reef

Keeping coral in a pico tank is awesome. Just a few coral frags will grow and fill out the small space relatively fast, creating the look of a mature reef tank. Parameters can be maintained with large, frequent water changes. You can achieve sufficient PAR levels with almost any nano-size reef tank LED light and the output from your filtration will create sufficient water flow.

Choosing the right types of coral to fit this environment will be critical because you only have room for a few corals and they will be close together. If you choose something aggressive or fast-growing, it can quickly out-compete other corals. Your best choices will be soft corals and small LPS corals. SPS corals can pose a challenge because they are more sensitive to water chemistry and it's difficult to supply the high-flow environment they need in such a small aquarium. In order to maintain multiple types of coral long-term, your likely going to need to "prune" corals as they grow alongside each other.

Best Pico Corals:

Mushrooms
Zoanthids and palythoa
Candy Cane
Favia
Acan
Micromussa

Fast Growing Corals:

Xenia
Button Polyps
Star Polyps
Yellow Polyps (parazoanthus)

Photo Credits: Tigahboy.h2o on Instagram

5. A Salty Garden

Macroalgae display tanks have become quite popular in recent years. These marine algae are relatively easy to care for and when curated carefully, you can achieve quite a beautiful display with a myriad of colors, shapes, and textures.

Common Types Of Macroalgae:

Caulerpa
Gracilaria
Halymenia
Ulva
Ogo

Some types of macroalgae are far more prolific than others and just like corals, you will need to prune and keep macroalgae in check in order to maintain a variety. If left to their own devices, usually one or two species will eventually outcompete the others.