What is needed for a saltwater fish tank?

Whether you have had a freshwater aquarium before or are entirely new to the aquarium hobby, this article will help you sort through all the options to determine what is needed for a saltwater fish tank?

Creating and maintaining a thriving, beautiful saltwater fish tank takes time, patience, money, and the right gear, gadgets, and supplies. Here is a quick summary of what is needed for a saltwater fish tank:

Equipment needed for a saltwater fish tank

1. The aquarium itself: The foundation of your setup. Choose a size that fits your space, budget, and maintenance commitment. Larger tanks are more stable (see below), but also more expensive and heavy.
   Common mistake: Underestimating the weight and space requirements.
2. A stand: Must support the full weight of the tank when filled with water, rock, and equipment. Using furniture not rated for aquariums risks collapse.
   Common mistake: Using an inadequate stand or placing tanks on uneven surfaces.
3. A lid: Prevents fish from jumping out and reduces evaporation. A secure, well-fitting lid is especially important for species known to jump.
   Common mistake: Skipping the lid or using a loose cover because many saltwater fish are notorious jumpers.
4. Lights: Essential for viewing and, if keeping corals, for supporting photosynthesis. Use a timer for consistent day/night cycles (8-10 hours/day).
   Trade-off: Basic lights suffice for fish-only tanks; reef tanks require higher-quality, spectrum-specific lighting.
5. Heater and/or Chiller: Maintains stable water temperature. Most saltwater species require 76-80°F (24-27°C). A chiller may be needed in hot climates.
   Common mistake: Choosing an undersized heater or placing it in an area with poor water flow, leading to temperature swings.
6. Water circulation pump: Provides water movement and oxygenation, mimicking natural currents. Essential for gas exchange and keeping detritus suspended for filtration.
   Trade-off: Too little flow leads to dead spots; too much can stress fish and corals.
7. Filter: If the tank is not filled with live rock, a filter is necessary for mechanical and biological filtration. Even with live rock, some prefer a filter for added water clarity.
   Trade-off: Canister and hang-on-back filters are easy for beginners; sumps offer more flexibility for advanced setups.
   Common mistake: Relying on biological filtration from live rock only without mechanical, denitrifying, or protein skimming components.
8. Gravel vacuum: Used for cleaning substrate and removing detritus during water changes.
   Common mistake: Neglecting substrate cleaning, leading to nutrient buildup.
9. Hydrometer or Refractometer: Measures salinity/specific gravity. A refractometer is more accurate and reliable than inexpensive swing-arm hydrometers, which can become inaccurate over time.
   Trade-off: Hydrometers are cheap but less reliable; refractometers cost more but provide precise readings.
   Common mistake: Trusting a faulty hydrometer and running the tank at improper salinity. This is advice I personally need to do a better job of applying for myself. I literally just had this issue.
10. Buckets: For water changes, mixing saltwater, and acclimating new livestock. Designate aquarium-only buckets to avoid contamination.
11. Plastic containers: Useful for catching, transporting, or acclimating fish and invertebrates.
12. Thermometer: For monitoring water temperature. Digital thermometers are more accurate and easier to read than stick-on strips.

Substrate and decorations needed for a saltwater fish tank

1. Live rock: Porous reef rock creates aquascape, provides hiding spots, and serves as the primary biological filter by hosting beneficial bacteria. The amount of live rock directly impacts your tank’s ability to process waste.
   Trade-off: Live rock is expensive but jump-starts biological filtration; dry rock is cheaper but takes longer to mature.
2. Live sand: Adds biological diversity and enhances the tank’s appearance. Live sand can help seed beneficial bacteria but is not strictly required.
3. Decorations: Personalize your tank and provide additional hiding places. Avoid non-aquarium-safe materials.

Supplies needed for a saltwater fish tank

1. Reef salt mix: For making salt water. Use only reputable marine salt mixes; never table salt or freshwater “aquarium salt.”
2. Test kits: For monitoring critical water parameters (see below).
3. Coral dip: Treats corals before adding them to the tank, reducing the risk of pests.
4. Kalkwasser or a Two-Part supplement: For calcium and alkalinity management, especially important in reef tanks.
5. Replacement filter media: If using a filter, plan to replace media regularly to maintain effectiveness.

Food needed for a saltwater fish tank

You don’t need to buy all of these all at once, but over time, it is generally good to provide a variety of options.

1. Live foods: Blackworms, brine shrimp, mysis shrimp, feeder shrimp; choose based on the species you keep.
2. Frozen foods: Brine shrimp, mysis shrimp, veggie blends; offer variety and watch out for special needs like certain angelfish species and sponges in their diet. There are blends for everything.
3. Pellets or flakes: Convenient, nutrient-packed prepared foods for daily feeding.
   • Trade off: Can add excess nutrients to the water column which would then fuel algae.

There are a lot more items that will be covered in this article that you could add, but the list above is what is needed for a saltwater fish tank.

Additional equipment that can be helpful for a saltwater fish tank

In addition to what is needed for a saltwater fish tank, there are a lot of optional items that are not 100% necessary but can improve your experience. Here are a bunch of the most popular and useful items to consider supplementing with what is needed for a saltwater fish tank. Some of these become essential as your tank grows in size or complexity:

1. Protein skimmer: Specialized equipment that removes dissolved organic waste. Strongly recommended for tanks over ~40 gallons, heavily stocked tanks, or reef setups. Helps maintain water quality and reduces maintenance.
2. Sump: A reservoir below the tank (usually in the stand) that increases water volume, hides equipment, and allows for more advanced filtration. Essential for large or complex reef tanks.
3. Refugium: A dedicated area for growing macroalgae and beneficial invertebrates, which help purify water and provide natural food. Valuable for nutrient export in reef tanks.
4. Target feeder for corals: Specialized gear to help feed corals directly. Useful if keeping corals that require supplemental feeding.
5. Magnet glass cleaner: Makes keeping the aquarium glass clear of algae easy. Highly recommended for tanks of any size.
6. Nets: For catching or moving fish, but often best used to gently guide fish into a container to minimize stress and injury.
7. Quarantine tank: For observing and treating new fish before introducing them to your main tank. Essential for disease prevention in any saltwater setup.
8. RO/DI system: Water purification system that produces pure water for mixing saltwater and topping off evaporation. Strongly recommended for reef tanks or areas with poor tap water quality.
9. Reactors: Hold media (like carbon or phosphate removers) that react with chemicals in the water. Useful for advanced water quality management.
10. Dosers: Small pumps that add nutrients or supplements consistently. Recommended for tanks with high coral demand or where manual dosing is impractical.
11. Automatic Top Off (ATO): Automatically replaces water lost to evaporation, maintaining stable salinity. Highly beneficial for tanks of any size, especially reefs.
12. Reef Journal: A place to plan, record progress, and track test results. Helps spot trends and troubleshoot issues.
13. New Saltwater Aquarium Guide: A comprehensive guide to setting up your new tank.

Upgrade prioritization: For fish-only tanks, focus first on a protein skimmer and ATO. For reefs, prioritize RO/DI, skimmer, and dosing solutions as your coral population grows.

Water quality: testing what is needed for a saltwater fish tank

Maintaining high water quality is everything in a saltwater tank. In some respects, success is as much about caring for the water as it is about caring for the fish in the fish tank.

Here are the most important water quality measurements to do what is needed for a saltwater fish tank. Understanding what each parameter means and how it affects your tank is critical:

• Salinity: Measures how much salt is in the water, typically as specific gravity. Too low or too high salinity stresses or kills marine life. Inaccurate readings (often from faulty hydrometers) are a common cause of livestock loss.
• pH: Saltwater needs a higher pH (typically 7.8-8.4) than freshwater. Low pH can stress or kill fish and corals; high pH can indicate excessive alkalinity or CO₂ loss.
• Temperature: Most saltwater fish come from warm, tropical reef waters. Fluctuations or extremes can cause disease and death. Use a reliable heater and thermometer.
• Ammonia: A poisonous pollutant produced by fish waste and decaying food. Should always be zero in a cycled tank. Any detectable ammonia is a red flag–often from overfeeding, new tank syndrome, or filter failure.
• Nitrites: An intermediate compound created when your filter processes ammonia. Should also be zero in a cycled tank. Detectable nitrites indicate an incomplete cycle or recent disturbance.
• Nitrates: The end product of the nitrogen cycle. Less toxic than ammonia or nitrite but still harmful at high levels. High nitrates often result from overstocking, overfeeding, or inadequate water changes. Persistently high nitrates can cause algae blooms and stress corals and inverts.
• Alkalinity: Indicates the water’s buffering capacity and is essential for coral health. Low alkalinity can cause pH swings and coral stress.
• Calcium: Critical for healthy corals and invertebrates. Low calcium impedes coral growth; high calcium can cause precipitation and cloudy water.
• Phosphates: A trace nutrient that becomes problematic in large quantities. High phosphates fuel nuisance algae and can inhibit coral growth.

Diagnostic tip: A sudden ammonia spike often means something has died or the filter is failing. Persistently high nitrates suggest overstocking, overfeeding, or insufficient water changes. Test regularly to catch problems early.

To test for and measure these water parameters, you will need equipment, including a hydrometer or refractometer for salinity and a thermometer for temperature. You will also need test kits or strips for measuring ammonia, nitrites, nitrates, alkalinity, calcium, and phosphates.

Check out this full-length article on the most important water parameters for more information.

Dealing with potential problems

We all face problems while trying to keep our saltwater fish tanks pristine and clean. The three most likely problems you will encounter are:

1. Nuisance algae: Usually caused by excess nutrients (nitrates, phosphates), inadequate water changes, or poor flow. Common types include dinoflagellates, diatoms, cyanobacteria, hair algae, bryopsis, and bubble algae.
   Prevention: Avoid overfeeding, maintain regular water changes, use RO/DI water, and ensure adequate flow. Early intervention is easier than waiting for an outbreak.
   Setup impact: Using uncured live rock or skipping RO/DI water increases risk.
2. Parasites: Saltwater ich, marine velvet, and other parasites often enter tanks with new fish or invertebrates. 
   Root cause: Lack of quarantine is the most common reason for parasite outbreaks.
   Prevention: Always quarantine new livestock for observation and treatment before adding to your display tank. Early detection and isolation are critical.
   Setup impact: Skipping quarantine can lead to tank-wide losses and is much harder to fix after the fact.
3. Unwanted hitchhikers: Creatures like aiptasia anemones, bristle worms, and red bugs often arrive hidden on live rock or coral frags.
   Root cause: Introducing uncured or uninspected live rock/corals.
   Prevention: Inspect and dip corals, source live rock carefully, and quarantine when possible.
   Setup impact: Early decisions about rock and coral sourcing have long-term effects on pest risk.

Related article: 23 Quick Tips for Dealing with Aquarium Algae

Related article: Treating saltwater ich

Related article: Hitchhiker’s guide to live rock

What is needed for a saltwater fish tank: the best first fish

The best first fish for a new saltwater tank will be relatively inexpensive, hardy, and proven by many people to be successful in an aquarium. Specific care guides and lists of the best first fish are their own topics, but to get you started, here are the results of a survey I ran with Saltwater Aquarium Blog readers. This is unique, personal data captured here that I am sharing with you. According to blog readers like you, the three of the best first fish:

1. Clownfish: 94% of aquarium enthusiasts reported success caring for clownfish
2. Wrasses: 89% reported success caring for wrasses
3. Cardinalfish: 88% reported success caring for cardinalfish

Related article: Powerful coral care and saltwater fish statistics

Related article: 5 Best saltwater fish for beginners

How many fish for a saltwater fish tank, and what are the best combinations?

The number of fish for a saltwater fish tank will vary based on the size of the tank, the size of the fish, the combination of fish, and the amount of space each one needs. To review custom recommendations, check out these popular stocking guides by tank size:

• Best saltwater fish for a 10-gallon saltwater tank
• Saltwater fish recommendation for a 15-gallon saltwater tank
• Best fish for a 20-gallon saltwater tank
• Best saltwater fish for a 30-gallon saltwater tank
• Saltwater fish for a 40-gallon saltwater tank
• Fish recommendations for a 55-gallon saltwater tank
• 75-gallon saltwater tank fish recommendations
• 90-gallon saltwater tank stocking guide
• 100-gallon saltwater tank stocking guide

When to add the first saltwater fish

The first appropriate time to add your first saltwater fish is after the tank has completely cycled. Let’s explore what that means. A fish tank, by definition, is a reservoir of water you keep in your house and ideally doesn’t leak. That means nothing goes in or leaves the tank without you handling the details.

The saltwater fish and invertebrates you add will go about their business and do their own biological functions if you catch my meaning.

You will also add food that won’t get entirely eaten. All of that stuff eventually creates waste. One of the key waste products that will build up (at first) is ammonia. Unfortunately, ammonia is a toxic chemical. 

Fortunately, naturally occurring bacteria will colonize your tank, all on their own, or with the help of additives or special products you can buy, like live rock and live sand. Those first, naturally occurring and beneficial bacterial will consume the ammonia and turn it into nitrites (spelling is important there, as you’ll see in a moment).

Those nitrites are problematic in freshwater but not-so-problematic in saltwater. However, either way, we are fortunate that there is another group of bacteria that like to consume the nitrites and leave nitrates behind as a waste product.

Once your tank has built up the natural colonies of bacteria that you need to do all that waste management, your tank is said to have cycled.

How to know your tank is cycled:

• Ammonia and nitrite both test at zero for at least 3-5 consecutive days after adding a source of ammonia (such as fish food or pure ammonia).
• Nitrate is present, indicating the cycle is complete.
• Do not rely on the number of days since setup or assume bottled bacteria or live rock guarantees instant cycling—always confirm with test kits.

Common misconception: Time alone does not determine readiness; only water tests can confirm a completed cycle.

If you add your first fish before that is done, you will burn them. Chemical burns. Nobody wants to see you create the next Joker (Batman reference) in your tank. 

So please check to see that your saltwater fish tank has cycled before adding your first saltwater fish to the tank.

Related: How to cycle a saltwater fish tank

What is needed for a saltwater fish tank: the best beginner corals

If you plan to add corals to your saltwater fish tank, an important first step is to pick those coral types that you are likely to have success with. Success breeds more success in this hobby. Back to that proprietary research survey among Saltwater Aquarium Blog readers, here are a few of the best beginner corals to add to a new saltwater fish tank:

1. Mushroom corals: 92% of people reported success with mushroom corals
2. Green star polyps: success was reported 85% of the time with GSP
3. Toadstool corals: 82% of people were successful with toadstool corals

Related article: 27 Best beginner corals

When to add your first corals

Determining when to add your first corals is a bit of a tricky topic. Some of the best beginner corals will act like pioneers, helping you colonize the new frontier you have created and help carve out a space and compete with the inevitable algae problem.

However, those first corals are also likely to succumb to the fluctuating water parameters and the problems that those nuisance algae will cause.

You certainly could start sooner if you were very eager to get your hands wet with corals, but I think a reasonable starting point estimate would be to wait until your tank has progressed through the various algae stages. 

While not every tank will experience all the stages, the first ‘algae’ to pop up are brown dinoflagellates, diatoms, cyanobacteria, hair and bubble algae, and then finally coralline algae and stability. 

Once those problem algae are out of the way and the coralline algae take over (should be between 6 months and a year), your tank is in the best shape it is going to be to give you the greatest chance of success with corals.

In all fairness, that might also be doing it the hard way, so if you want to get started a little early, start with that list above of the hardiest beginner corals because they are fast enough to potentially out-compete those problem algae.

Best cleanup crew: what is needed for a saltwater fish tank

One of the coolest things needed for a saltwater fish tank is also one of the most fun–it is called a clean-up crew. What is a clean-up crew? It is a combination of invertebrates that will help stir up the sand, eat unwanted or leftover food, munch on algae and help remove the unwanted things.

Here are a few of the best cleanup crew members:

1. Hermit crabs: able to climb to the hardest-to-reach places, they are great scavengers
2. Cerith snails: MVP of the clean-up crew. They are small but tackle the tough problems
3. Emerald crabs: Make short work of hair algae problems

Related: 23 Interesting invertebrates that also eat algae

Maintenance tasks: what is needed for a saltwater fish tank?

Each day

• Feed your fish 2-3 times. Purpose: Regular feeding supports health and growth. If skipped: Fish may become stressed or malnourished. Note: Avoid overfeeding, which leads to water quality issues.
• Wipe down aquarium glass to clean off algal film. Purpose: Maintains visibility and prevents algae buildup. If skipped: Algae can become harder to remove and may spread.
• Dump the protein skimmer cup to remove the skimmate. Purpose: Prevents overflow and keeps skimmer working efficiently. If skipped: Skimmate can return to the tank, degrading water quality.

Each week

• Perform a 10-20% water change (at least until you get the hang of it). Purpose: Removes accumulated nitrates, phosphates, and replenishes trace elements. If skipped: Waste builds up, leading to algae and stressed livestock. Adjust frequency: As your tank matures and stocking stabilizes, you may be able to reduce frequency, but always monitor water parameters.
• Test your water 2-3 times each with all the kits or strips you own, targeting the major water parameters, and record it in your Reef Journal. Purpose: Early detection of problems. If skipped: Issues may go unnoticed until they become severe.
• With a wet rag (fresh water, no chemicals,) wipe away any accumulated salt deposits on the lid (called salt creep, it will keep growing if you don’t get rid of it). Purpose: Prevents equipment corrosion and keeps the tank looking clean.
• Replace any water you lost to evaporation with aged, chlorine-free fresh water (RO/DI is best, but aged tap water is fine). Keep track of how much skimmate you’ve removed because you want to keep salinity neutral, and the skimmate removed will be saltwater, not freshwater. Purpose: Maintains stable salinity. If skipped: Salinity will rise, stressing livestock.
• Clean out the protein skimmer cup and neck to aid in efficient skimming. Purpose: Maintains skimmer performance.
• Feed your corals 1-2 times. Purpose: Supports coral health and growth.

Adjusting maintenance: As your tank matures, you may find that some tasks (like water changes) can be done less frequently if water quality remains stable, but always let test results guide your routine. Heavily stocked or newer tanks typically require more frequent attention.

Cost and how much money: what is needed for a saltwater fish tank

You can truly spend however much money you want on a saltwater tank, and you will probably spend more money than you think. In a 2022 survey of Saltwater Aquarium Enthusiasts, 18% spent $500 or less on their setups, but the median cost was between $1,000- $1,500.

As you can see from the chart above, however, the initial setup cost was spread throughout the range. In addition, there was a sizeable number of people at every cost threshold, suggesting that the upfront investment cost is somewhat up to the aquarium owner to decide.

Expert Tips & Common Beginner Mistakes to Avoid

• Install a grounding probe: Prevents electrical shock and protects both you and your livestock.
• Use nets wisely: Nets are best for gently guiding fish into a container, not for direct capture, which can injure delicate fins or scales.
• Mix live rock with dry rock: Save money by starting with mostly dry rock and seeding it with a small amount of live rock—over time, all rock becomes “live.”
• Quarantine all new livestock: Skipping quarantine is the #1 cause of disease outbreaks. Always observe and treat new fish and corals before adding to your display tank.
• Don’t trust cheap hydrometers: Inexpensive swing-arm hydrometers are notorious for drifting out of calibration. Invest in a refractometer or regularly calibrate your hydrometer.
• Don’t rush the cycle: Adding fish before ammonia and nitrite are zero is a common cause of livestock loss.
• Don’t overstock or overfeed: Both lead to water quality issues and algae outbreaks. Start slow and add livestock gradually.
• Keep a reef journal: Track water parameters, livestock additions, and maintenance. This helps troubleshoot and spot trends before problems escalate.
• Use aquarium-only buckets and tools: Prevents contamination from soaps, cleaners, or chemicals.
• Plan for upgrades: It’s easier to add equipment (like a sump or skimmer) early than to retrofit later.

Related: Best saltwater aquarium tips for beginners

Quarantine

When I had freshwater tanks, I never quarantined them. I also never worried about it. Sure, diseases and parasites showed up, but I just ran out to the store, bought some meds, turned my tank blue or green for a few days, and the problem was over. 

I’m sure I also suffered my share of losses, but freshwater fish are cheap. I don’t mean to be callous. Just saying I never gave it much attention.

When I converted to the saltwater aquarium hobby all those years ago, I brought those bad habits with me, arrogantly reinforced by my self-perceptions of freshwater success.

I’m here to report that things ended badly for me twice. I’m talking total tank crashes due to crazy parasite problems. You can’t treat parasite problems effectively in a reef tank because anything you would use (that works!) will kill your invertebrates and corals.

The only way to treat parasites is in isolation. It is tough to get fish out of a reef tank, and it is challenging to eradicate parasites once they get in your reef tank. The solution to these problems is quarantine. Please read up on it.

Trade off: I know you may be scratching your head right now, thinking, wait, I need another mini tank before I can use my regular tank? A lot of people legitimately don’t have the space. I get it. Been there, done that, got the t-shirt. Nobody is judging, it’s a trade off and we all make them. Go have fun.

Related: How to quarantine for a saltwater tank

What is needed for a saltwater fish tank that is different from freshwater?

There are a lot of similarities between keeping a freshwater tank and a saltwater fish tank, but there are also a few unique elements needed for a saltwater fish tank.

Similarities with freshwater

The fundamentals of managing a saltwater fish tank are essentially the same as with freshwater–you need to understand the care needs of the fish you want to keep, and you need to meet them while also maintaining stable, pristine water conditions in the tank.

• A biological filter converts waste ammonia into nitrates.
• Water pumps help oxygenate and circulate the water
• Heaters warm up the water to tropical temperatures
• Water changes and maintenance keep things stable. 

A saltwater fish tank with corals is more like managing a planted freshwater tank and/or delicate fish like discus.

What is needed for a saltwater fish tank that is different from freshwater

Corals are not plants and not exactly traditional ‘animals’, per se, but they have care needs similar to both. That means they need high-quality lighting, like plants, but also need to be fed, like animals, and adequate water flow is essential to helping them get enough oxygen and remove their waste.

Many fish and invertebrates are more sensitive to fluctuations in water quality than the freshwater hobby.

Building and maintaining a saltwater tank is much more expensive.

Parasites, diseases and pests can be catastrophic and cause much more damage in saltwater (which is also much more expensive).

Biological filtration is vital in both fresh and saltwater, but in saltwater fish tanks, special rocks called live rocks, are placed inside the tank and serve as the reservoir for the bacteria that help clean the water. That is very different from a freshwater tank, where those bacteria are generally housed on a biowheel or in the sponge inside the filter.

This may have seemed obvious; salt water is needed for a saltwater fish tank. But, that isn’t made with table salt, or even the small box of ‘aquarium salt’ on the shelf at your big box store. Saltwater is made from a blend of salts and nutrients to recreate the specific levels of major and trace elements as ocean reefs.

Common freshwater-to-saltwater transition mistakes:

• Using table salt or freshwater aquarium salt instead of a marine salt mix. Reason: Marine species require a precise blend of salts and trace elements not found in table or freshwater salt.
• Skipping quarantine because it “wasn’t needed” in freshwater. Reason: Marine parasites are harder to treat and can wipe out entire tanks.
• Assuming disease treatments are the same. Reason: Most effective marine medications are toxic to invertebrates and corals, making in-tank treatment risky or impossible.
• Underestimating sensitivity of marine species to water parameter swings. Reason: Many saltwater fish and inverts are less tolerant of rapid changes than typical freshwater species.

Related: How to make saltwater for a saltwater fish tank

Related: Converting from freshwater to saltwater

Is it better to have a small tank or a larger tank? 

Many people in the echo chamber reiterate some old standby advice that bigger is better in the saltwater aquarium hobby, but that is not always the case.

Bigger almost always means more expense, and it also almost always means more work- unless you have additional equipment to help make the work more manageable. At that point, you need to see my first point, which means that it means more expense.

Bigger tanks also weigh a lot more, which can often limit your options of where you can keep the tank or even require you to structurally reinforce your floor. 

Here’s what my crawl space looks like:

What was that point I was making? Oh, right, bigger is NOT always better.

Why are larger tanks more stable? Larger water volumes dilute toxins (like ammonia or nitrate) and resist rapid temperature swings (thermal inertia). This means mistakes or equipment failures have less immediate impact, giving you more time to correct problems.

Decision framework for choosing tank size:

• If you value stability and have the budget and space, go larger (40+ gallons). Larger tanks are more forgiving of mistakes and parameter swings.
• If you want lower cost and easier maintenance, go smaller (10-30 gallons), but be prepared for more frequent intervention and careful monitoring.
• Consider your lifestyle: If you travel often or have limited time, a larger, more stable tank may be less stressful. If you want to experiment or have limited space, a smaller tank may be a better fit.
• Experience level matters: Beginners often find mid-sized tanks (20-75 gallons) offer the best balance of stability, cost, and manageability.

Smaller can be less expensive and easier to manage. Chores will take a fraction of the time, and you’ll run out of space sooner, which means it will cost you less. In addition, you will need less and smaller equipment, so running costs will also be lower.

With that said, people say bigger is better because water is generally pretty good at staying stable, unless we make it up, and a lot of water is better at staying stable than a little bit of water. So, since stability is a big part of the game here, size has THAT advantage.

But contrary to the norms here, it makes a lot of sense to start out relatively small. You can get a sense of how easy or hard it is to manage a saltwater fish tank without spending a fortune.

You also eliminate the risk that your new hobby feels more like a part-time job that you have to pay for.

You could start with any size tank you want, but for me, the sweet spot is between 20 gallons and 75 gallons. 

Styles of saltwater fish tanks

What is needed for a saltwater fish tank will vary a bit based on what style of aquarium setup you want to have. However, here are a few ideas to get you started.

Fish Only

A fish-only saltwater tank is the easiest type of aquarium to set up and is the most like a freshwater fish-only aquarium. You need good filtration, enough aquascape, and decorations to make your tank look great and make your fish feel safe, but it is as simple as you can get.

Having a fish-only tank does allow you to keep certain species that might otherwise be problematic in combination with certain species.

For example, you could create a community of aggressive saltwater fish species that would not be appropriate for a community tank. However, many large, aggressive fish are also some of the easiest to care for (as long as you keep them separate from their prey). 

You could also potentially keep some of the more delicate non-reef-safe fish, like large angelfish or butterflyfish. But keep in mind that would be a high complexity/difficulty tank.

Fish Only With Live Rock (FOWLR)

A FOWLR tank is a Fish Only With Live Rock tank. The name says (most of) it all. You have fish and live rock to create a natural substrate and performing the biological filtration for the tank, but you don’t have corals. 

This is often the gateway tank that people start with. Once success has been reached with saltwater fish, people often want to create a mixed reef–and if you start out with a live rock aquascape, the ‘bones’ of the tank will already be there for you to put your corals on when, and if the time presents. 

There aren’t any advantages between FOWLR vs. FO other than ease of upgrade and a more natural look/feel.

Community Reef Tank

Many of us dream of that community reef tank–re-creating the coral reefs we see when we snorkel, scuba dive, or watch TV programs. Seeing fish and corals living harmoniously, beautiful colors flashing and swaying in the current. 

This type of fish tank requires careful planning, special equipment (detailed above), and patience, but it is a very achievable goal.

Conclusions

Hopefully, you have enjoyed reading this article about what is needed for a saltwater aquarium. There are plenty of links in each section to dive deeper and learn about specific topics. If you have questions not answered here or there, please drop a comment below or join the newsletter to send me an email. 

I look forward to connecting with you.