Fish
Fish are usually the first animals people get excited about, but that cute little fish at the store may not stay little—or peaceful.
- How big will it get?
- Will it get along with the other fish?
- What order should you add everything?
Fish, coral, cleanup crew, and more
Saltwater Aquarium Livestock Guides
Choosing livestock is one of the most exciting parts of building a saltwater aquarium. It is also where things can get complicated really fast if we buy first and ask questions later.
I built these guides to help you figure out what actually fits your tank, what can wait, and what I would skip. Start with the animal you are thinking about, and we will work through the important stuff together.
Start with what you want to add
What Do You Want to Add to Your Tank?
Fish? Coral? A cleanup crew? Pick the group you are interested in and we will take it one step at a time. You do not need to figure out the entire tank today.
Corals & Anemones
Corals can be a great next step. Anemones are different. They need a more established tank, stronger lighting, protected pumps, and a little more patience.
- Does your tank have the right light and flow?
- Where will it go as it grows?
- Is the tank actually ready for an anemone?
Cleanup Crew
A cleanup crew can help, but only if you choose animals for the job your tank actually needs. More snails and crabs are not automatically better.
- What are you trying to clean up?
- How many animals do you really need?
- Will there be enough food for them?
Macroalgae
Macroalgae can look great in the display or do useful work in a refugium. It can also grow everywhere if you choose the wrong kind or stop pruning it.
- Do you want it for looks or filtration?
- Where will it grow, and how will you control it?
- Is this actually a nuisance algae problem instead?
Other Invertebrates
Shrimp, urchins, sea stars, clams, and specialty crabs can be incredible animals. They also have very different diets, space needs, and levels of difficulty.
- What exact animal are you buying?
- What will it eat, and can it get hurt?
- What will you do if it does not work out?
Learn the animals before you shop
Learn to Recognize Common Aquarium Animals
Want a simple way to get better at identifying the animals you see at the fish store? Practice with flip cards for common saltwater fish, corals, macroalgae, cleanup crew members, and other invertebrates. Look at the photo, make your best guess, and then flip the card to check your answer.
Beginner questions
Saltwater Aquarium Livestock FAQ
What should I add first to a new saltwater aquarium?
There is no single first animal that works for every tank. Make sure the aquarium is cycled and stable, then look at the tank size, the animals you eventually want, and the food and habitat the first animal will need.
How long should I wait before adding fish or coral?
Do not rely on one calendar date. Make sure the cycle is complete, the temperature and salinity are stable, the equipment is working, and you can repeat the basic maintenance routine. Those things matter more than the number of days since you added water.
Can a cleanup crew fix an algae problem?
Sometimes the right snail, crab, or urchin can help with a specific problem. But first you need to identify what is growing and why. A cleanup crew cannot replace better lighting, nutrient control, manual removal, or regular maintenance.
Are anemones beginner livestock?
Not automatically. A Bubble-Tip Anemone needs a stable tank, appropriate light and flow, room to move, and protected pump intakes. And just so you know, clownfish do not need an anemone.
Does “reef safe” mean an animal will never cause a problem?
No. “Reef safe” is a useful starting point, but it is not a promise. The exact species, the individual animal, its adult size, how hungry it is, and what else lives in the tank can all change the answer.
Should I quarantine or inspect new livestock?
Yes, but the process depends on what you are buying. Fish quarantine is not the same as inspecting and dipping coral, and neither one is the same as observing an invertebrate or checking macroalgae for hitchhikers. Use the guide for the exact animal.
Before moving on to Step 5
Make sure you can care for the animal after you buy it
A fish, coral, snail, or shrimp does not just need a safe tank today. It needs a routine you can keep doing next week and next month. Make sure testing, feeding, water changes, and basic equipment care are already part of the plan.