What Can I Put In My Aquarium Besides Fish – A Complete Guide

Do you ever look at your glass box and feel like something is missing, even though your fish are thriving? You are not alone. Many hobbyists eventually find themselves asking, “what can i put in my aquarium besides fish” to add more character and diversity to their underwater world.

The good news is that the world of freshwater invertebrates and aquatic plants is just as rewarding—if not more so—than keeping traditional fish. In this guide, I’ll walk you through the most vibrant, hardy, and fascinating creatures that will turn your tank into a thriving ecosystem.

Whether you are looking for a dedicated cleanup crew or a “centerpiece” invertebrate, we are going to explore every viable option for your setup. Let’s dive into the incredible variety of life that exists beyond the world of fins and scales!

The Colorful World of Freshwater Shrimp

Shrimp have exploded in popularity over the last decade, and for good reason. They are the ultimate busy-bodies of the aquarium, constantly picking at algae and biofilm with their tiny claws.

If you are a beginner, I highly recommend starting with Neocaridina davidi, commonly known as Cherry Shrimp. These hardy little gems come in a rainbow of colors, including deep red, neon yellow, and even striking blue velvet.

For those with a bit more experience and access to reverse osmosis (RO) water, the Caridina species offer even more intricate patterns. Crystal Red Shrimp or Blue Bolts are stunning, though they require more specific water parameters to thrive.

Why Shrimp Are a Great Choice

Shrimp add a sense of scale and movement that fish simply cannot replicate. They are also incredibly low-impact on your bio-load, meaning you can keep a colony of 20 in a small 5-gallon tank.

Watching a “shrimp frenzy” during feeding time is one of the most entertaining sights in the hobby. Plus, if they are happy, they will reproduce readily, providing you with a self-sustaining population of tiny cleaners.

Snails: The Essential Cleanup Crew

Many beginners view snails as “pests,” but experienced aquarists know they are unsung heroes. If you choose the right species, snails are beautiful, functional, and full of personality.

Nerite Snails are perhaps the best algae eaters in the world. They won’t reproduce in freshwater, so you never have to worry about an infestation, and their shells feature gorgeous “zebra” or “tiger” patterns.

If you want something more interactive, look at Mystery Snails. They grow quite large, have long, flowing antennae, and can actually be seen “parasailing” from the top of the tank to the bottom.

Managing Your Snail Population

To keep your snails healthy, ensure your water has enough calcium for their shells. A piece of cuttlebone tucked into the filter or feeding calcium-rich “snello” will keep their shells thick and crack-free.

While Nerites are safe, be cautious with Bladder or Ramshorn snails. While beneficial, they can overpopulate quickly if you are overfeeding your tank, so keep your maintenance schedule tight!

Miniature Monsters: Crayfish and Crabs

If you want something with a bit more “edge,” the world of crustaceans is for you. However, you must be careful, as many larger crayfish are notorious escape artists and opportunistic hunters.

For a community-safe option, I always suggest the Mexican Dwarf Crayfish (CPO). They stay small (about 2 inches), are a brilliant fiery orange, and generally leave healthy fish and plants alone.

If you prefer crabs, the Thai Micro Crab is a fascinating, shy creature that looks like a tiny underwater spider. They are completely peaceful and spend their time hiding in moss or sponge filters.

A Warning on Larger Crustaceans

Avoid the large “Electric Blue” crayfish unless you are prepared for a species-only tank. These beautiful monsters will treat your expensive plants like a salad bar and your sleeping fish like a midnight snack.

Always ensure your aquarium has a tight-fitting lid. Crabs and crayfish are surprisingly strong and will find even the smallest gap in your hood to go on a “land exploration” that rarely ends well.

Amphibians for the Specialized Setup

When people ask “what can i put in my aquarium besides fish”, they often forget about our four-legged aquatic friends. Amphibians add a completely different vertical dimension to a tank.

African Dwarf Frogs (ADF) are a classic choice. They are fully aquatic, meaning they never need to leave the water, and their goofy behavior is a joy to watch as they “zen” out at the surface.

For a truly unique experience, consider the Axolotl. These “Mexican Walking Fish” are actually salamanders that stay in their larval stage forever. They require cold water and a large footprint, but their “smiling” faces make them incredible pets.

Caring for Aquatic Amphibians

Amphibians are highly sensitive to water quality because they breathe partially through their skin. Regular water changes and a high-quality de-chlorinator are non-negotiable for these sensitive creatures.

Be mindful of tank mates; frogs have poor eyesight and may accidentally nip at a fish’s fin during feeding. It is often best to keep them in a dedicated setup where they don’t have to compete for food.

The “Green” Inhabitants: Aquatic Plants

Sometimes the best thing you can put in your tank besides fish isn’t an animal at all—it’s a lush forest of plants. A high-tech “aquascape” can be more beautiful than any fish collection.

Start with “epiphytes” like Anubias or Java Fern. These plants don’t even need soil; you simply glue or tie them to rocks and driftwood, and they pull nutrients directly from the water column.

If you want a “carpeted” look, plants like Monte Carlo or Dwarf Hairgrass can create a stunning green meadow across your substrate. This provides a natural habitat that makes your other inhabitants feel safe.

The Benefits of a Planted Tank

Plants act as a natural filter, absorbing nitrates and ammonia that would otherwise harm your livestock. They also compete with algae for nutrients, helping to keep your glass crystal clear.

Don’t be intimidated by the tech! Many plants thrive in low-light conditions without CO2 injection. A simple LED light and a weekly dose of liquid fertilizer are often all you need to get started.

Practical Considerations for what can i put in my aquarium besides fish

Before you rush out to the local fish store, you need to consider how these new additions will change your maintenance routine. Invertebrates and amphibians have different needs than your standard guppy.

Most invertebrates are highly sensitive to copper. Many common fish medications contain copper, which is lethal to shrimp and snails. Always read the label before treating a tank that houses “non-fish” inhabitants.

Water hardness is another critical factor. While most fish are adaptable, shrimp and snails require minerals like calcium and magnesium to molt and grow their shells properly.

Finding the Right Balance

If you are wondering “what can i put in my aquarium besides fish” to help with maintenance, remember that no animal is a substitute for a gravel vacuum. They help, but they still produce waste!

Aim for a balanced ecosystem. A mix of a few snails, a colony of shrimp, and plenty of live plants creates a biological “buffer” that makes your aquarium much more stable in the long run.

Compatibility: Who Plays Well Together?

The biggest mistake beginners make is mixing species that view each other as food. For example, large Cichlids will make expensive snacks out of your colorful Cherry Shrimp.

The best tank mates for invertebrates are small, peaceful nano-fish like Chili Rasboras, Neon Tetras, or Otocinclus Catfish. These fish have mouths too small to bother adult shrimp.

If you are keeping Vampire Shrimp or Amano Shrimp, they are large enough to live with slightly bigger fish, but always provide plenty of hiding spots like caves, PVC pipes, or dense moss.

Creating Hiding Spots

Invertebrates feel most comfortable when they have “safe zones.” Using stacked rocks, cholla wood, or ceramic “shrimp flats” gives them a place to retreat when they are molting and vulnerable.

A heavily planted tank is the best way to ensure everyone gets along. The more visual breaks you have in the aquarium, the less likely your inhabitants are to stress each other out.

Frequently Asked Questions (FAQ)

Can I keep shrimp and snails together?

Yes, absolutely! Shrimp and snails are the perfect duo. They occupy different niches and rarely compete for food, making them an excellent choice for any community tank.

Do I need a heater for an invertebrate tank?

It depends on the species. Cherry Shrimp prefer cooler water (68-74°F), while Mystery Snails and African Dwarf Frogs need tropical temperatures (75-80°F). Always research your specific species.

What do I feed my aquarium invertebrates?

While they eat algae, you should supplement their diet with sinking pellets, blanched vegetables (like zucchini or spinach), and specialized “shrimp cuisine” to ensure they get proper nutrition.

Will my shrimp overpopulate the tank?

Shrimp will only breed up to the limit of the food supply. If you don’t overfeed, the population will naturally level off. Many hobbyists actually sell their excess shrimp back to local stores!

Are there any “non-fish” that eat algae?

Nerite Snails and Amano Shrimp are the gold standard for algae control. They are much more effective than many “algae-eating” fish and have a much smaller impact on your water quality.

Conclusion: Expanding Your Aquatic Horizons

Deciding “what can i put in my aquarium besides fish” is the first step toward becoming a more well-rounded and successful aquarist. By stepping outside the world of fins, you open up a whole new realm of biology.

From the vibrant colors of Neocaridina shrimp to the functional beauty of Nerite snails and the lush textures of aquatic mosses, these additions make your tank feel like a true slice of nature.

Remember to start slowly, check your water parameters, and always provide plenty of cover. Your aquarium is a living canvas—don’t be afraid to paint it with more than just fish!