Author: Mark Valderrama

The saltwater aquarium you start with shapes everything that comes after. your equipment choices, your livestock options, your maintenance routine. I’ve watched beginners pick tanks that were too small for their goals, or all-in-ones that couldn’t be upgraded, and they ended up restarting from scratch within a year. After setting up and advising on dozens of reef systems over 25 years, I have a clear picture of what actually matters when you’re making this choice.

The saltwater aquarium you choose at the start determines nearly every other decision you’ll make. what equipment fits, what fish you can keep, what your maintenance looks like long-term, and what your total budget needs to be. After 25 years in this hobby and helping countless people set up their first saltwater tanks, the advice I give most often contradicts what beginners expect: bigger tanks are more stable and more forgiving, not harder. The “start small” instinct usually leads to frustration. And the tank itself is just the beginning of the budget conversation. In this guide I walk through everything you need to consider when selecting a saltwater aquarium.

Owning a successful aquarium depends greatly on the time of time spent planning and researching the setup for the fish and/or corals you choose to have.  There are a large number of choices when it comes to tank selection.  This article should provide you some in-depth detail on saltwater fish tank selection and what to look for when purchasing an aquarium.

Saltwater Aquarium Budget

I’m not going to sugarcoat it.  A fish tank in general is expensive and a saltwater tank is even more expensive.  If you put me on the spot without any research whatsoever and ask me “how much a saltwater tank setup will cost” my answer is “At least $1,000.”  Keep in mind, however, that a lot of the costs will be upfront investments in the tank, equipment, rock, stand, substrates, etc.  You can certainty spend less on a smaller setup and can cut cut with DIY work or used equipment, but I am going to assume that you are not a big DIYer.  Over time, as you get more advanced in this hobby, it is natural to begin DIY solutions, but beginners should generally stay away from DIY.  If you are going to DIY, I would suggest you join a local aquarium society.  There are plenty of very seasoned hobbyists in an aquarium society who will be more than willing to teach you the ropes or even offer to do DIY solutions for cheap (e.g. – drill your tank or build you a sump).  

Aquarium Societies are Treasure Troves of Knowledge

Saltwater Tank Size

Tanks come in a variety of size, but there are four rules to keep in mind that will help with your selection:

1. The more gallons, the more stability – bigger is better
2. The longer the tank, the more room for fish to swim
3. The wider the tank, the easier to aquascape
4. The taller the tank, the harder for maintenance

With these rules explained, tanks are usually divided by lengths.  The key lengths are 2, 3, 4, and 6 feet.  Most tank manufacturers do not produce 5 foot length tanks and if you find one, you may have a hard time getting a stand.  I recommend 3, 4, or 6 foot length tanks. 3 feet I feel is the best length for those on a budget or a beginner.  4 feet allows for a complete mixed reef setup and most lighting systems are designed for 4 foot aquariums.  6 feet in length is when you get to the territory of being able to house larger fish like tangs.

A beautiful 3 foot 40 Gallon Breeder tank

Tank height is another consideration.  When you go over two feet in height, you will have additional room for fish to swim up and down instead of just side to side, but you will sacrifice ease of maintenance.  Saltwater tanks more than 2 feet in height will be out of reach for most hobbyist’s hands so you will have trouble cleaning algae.

Tank Placement

Your aquarium is going to be a sizable investment and will easily become the showcase and talk of your home.  When friends and family visit your home, everyone is going to want to see your tank.  Because of this, you really want your aquarium in a place where you can enjoy it on a daily basis.  That being said, there are a few rules to follow when it comes to placement:

1. Keep your tank out of direct sunlight – this will lead to spikes in temperature and algae outbreaks
2. Think of the first floor of your home or basement before upstairs – any tank over 40 gallons in size is going to weigh a sizable amount.  Tank water is about 8 pounds per gallon and then you will have sand and rock as part of the mix.  If your tank will be directly placed on a floor that is part of the foundation, there are virtually no concerns with placement.
3. Place your tank near an outlet – or get one installed by an electrician.  Your tank is going to be using power to run and so the closer the better.  Make sure it is on its own circuit if you plan on having a tank of more than 40 gallons as a full-setup aquarium will draw a lot of power.
4. Do not place your tank directly below a vent –  heating and A/C vents can drastically change the temperature of your aquarium.  Having a stable water temperature is critical to a healthy aquarium.  Placing your tank away from a vent will prevent this issue.
5. If you are dead set on having an aquarium upstairs – hire a structural contractor to get advice if you are going to place a 40+ gallon tank upstairs. Better safe than sorry.  A couple of hundred dollars could be worth tens and thousands of dollars of prevented repairs.
6. Level the area – if your placement is slightly off-level, get some shims to adjust.  If the location is way off-level – consider another spot

An Aquarium is Best Placed Away from Direct Sunlight

Flooring

Flooring is another consideration to keep in mind.  The most ideal floor for a tank would be directly on a foundation or on top of the tile.  Carpet can be risky because water spills will eventually build mold in the padding. Laminate can also be hit or miss, with only the higher quality laminates being ideal and sealing being key.  Hardwood floors are not ideal because the saltwater from your tank can eventually wrap the hardwood.   You can seal your hardwood, but it is at your risk.  If you have a spill, you will need to clean it up right away.  Having a wet/dry vacuum can be a lifesaver for such times.

Shape of Fish Tanks

You will find multiple shapes if you go shopping for an aquarium.  We are going to focus on the four most popular on the market

• Rectangle – Most flexible and ideal shape for fish, width can be an issue in long formats
• Corner – Good for corner setups, but sacrifices on swimming space
• Bowfront – Great for viewing, but more expensive than rectangle shaped
• Cube – Great for coral aquascaping, but sacrifices length for larger fish

Our recommendation is to go with a rectangular tank.  They offer the most flexibility, most economical, and most fish will prefer long over tall setups.

Types of Tanks

In the industry there are four types of tanks you find available for purchase:

• Standard Aquariums – Usually found at general pet stores
• Reef Ready Aquariums – Pre-drilled and ready for a sump
• All-In-One Aquariums – Pre-designed for ease of use
• Custom Built Aquariums – Very expensive, but showcase quality

Standard Glass Aquarium

Standard aquariums are mass-produced aquariums made with glass. They are of good quality and will come with black trim and rims to provide structural support.  The vast majority of these tanks will have tempered glass on the bottom of the tank, which will limit your drilling of the tank if you chose to do so to the back of the aquarium.  Many hobbyists will purchase these tanks and customize them by drilling them and even painting the back of the tank.  Standard aquariums are the best choice for a budget-conscious build.

Reef Ready Tank

Reef Ready Aquariums are aquariums that are pre-drilled and will come with an overflow system.  An overflow system is designed to skim the water surface of your aquarium to pull dissolved organics and waste out of your tank.  These tanks are designed to work with a sump setup.  A reef ready aquarium is the best choice for flexibility and long-term investment.  They provide the best starting point for a hobbyist looking to build a complete system.  The main advantage from a reef ready system over a drilled standard tank is that the reef ready tanks are drilled at the bottom.  This allows you to setup a very clean and seamless look in the back of the tank without pipes sticking out.  Many of the new reef ready tanks coming out these days are coming equipped with innovative overflow systems as well.  If you want to start out on the best foot possible, a reef ready tank is the way to go.

All-In-One Tank

All-In-One Aquariums are a recent development in the industry.  They are tanks complete with overflows and even sumps to provide either a fully integrated system or as close to a plug-and-play solution as possible.  Some All-In-One will have a Sump in the back of the tank, which will eliminate plumbing that would be required in a sump setup.  All-In-One Aquariums can be more expensive then a full setup Reef Ready Aquarium and can have limitations over a customized setup.  One of the biggest limitations is the equipment you can place in it.  For example, sometimes the protein skimmer chamber may be very small so you will be limited on the type of skimmer you can place or the sump that comes with the all-in-one may not have room for a refugium.   If you are looking for ease of use and a seamless look (as many of these tanks have wonderful aesthetics), an All-In-One Aquarium would be the choice for you.

Jimmy Butler’s Custom Boom Box Tank as seen on “Tanked”

Custom Built Aquariums are the most expensive setups.  You can obtain an extremely unique and world-class look.  Custom tank makers are usually found locally as custom aquarium makers are very seasoned hobbyists or companies that create custom aquariums.  If you want the “Tanked” look, a custom-built aquarium is where to look to.

Glass vs. Acrylic Tanks

Glass vs. acrylic is a common debate when it comes to tank selection.  Below is a table to show the strengths and weaknesses of glass and acrylic:

Characteristic	Glass	Acrylic
Weight	Glass is usually about 4 times heavier than acrylic and up to 10 times heavier on larger aquariums	Lightweight and easier to move
Breaking and Cracking	With a strong enough force – Glass will crack and leak	Very impact resistant
Support	Glass can support itself over distances so they can be placed in stands with an open top with little to no risk	Needs support throughout the length of the tank.  Stands are limited due to this.
Clarity	The thicker the glass, the more noticeable the distortion.  Distortion can be mitigated in thicker glass by the use of low-iron glass.	No distortion in clarity – superior to glass even against low-iron glass.
Scratching	Very difficult to scratch.  You can even clean algae with a razor blade and be fine with glass	Prone to scratching.  Fish with strong jaws can directly scratch acrylic and you can even scratch the outside accidentally with jewelry.  The outside scratches, however, can be repaired with a repair kit.
Cost	Generally cheaper and mass-produced	Generally more expensive due to shipping

Overall, I would recommend going with a glass aquarium as the pros outweigh the cons.  You might want to consider acrylic or even plywood though if you are considering a tank over 500 gallons due to the weight and clarity issues of glass.

Drilling vs. Not Drilling a Tank

A common consideration when one is deciding between a standard tank or reef-ready tank is drilling vs. not drilling.  There are many benefits to drilling your tank – the most beneficial being the inclusion of a sump.  When you drill your tank and install a sump, your setup becomes extremely flexible with equipment.  You will be able to purchase the best equipment, hide everything outside of the tank, be able to build a section for beneficial reef organisms (known as a refugium), install tank maintenance automation (auto water top-offs, controllers, and dosing pumps), and a separate work area for most of your maintenance outside of your display tank.  You miss out on all this flexibility when you do not drill and going from a not drilled to a drilled setup would require a hang-on overflow.  Hang-on overflows have usually been fail-prone, the main reason why we chose not to carry them.  The drilling decision is something made early on because of the large amount of work required to transition to a drilled setup.  Therefore, I feel that it is best to strongly consider a drilled setup from the start.

A Standard Tank Can be Drilled with Basic Power Tools

Rimmed vs. Rimless Fish Tanks

Rimmed tanks have been the tried and true traditional aquarium type for many years.  There has been a development of rimless tanks that have a very modern, aesthetically pleasing look.  Many higher-end aquariums you will come across will have rimless designs.  They are very beautiful aquariums, with main drawback being the price difference and water possibility leaking out when you clean algae near the top of the tank.  You can’t go wrong either way.

Rimless Tanks Have Great Aesthetics!

Low-Iron vs. Traditional Glass Tanks

These days, there are tanks you can purchase that have what the industry calls “low-iron” or “high-clarity” glass.  This is glass with low amounts of iron, which remove the green tint you may see from a standard tank.  It is a softer glass that will scratch easier than traditional glass (though still way more scratch resistant than acrylic).  Low-iron glass is more expensive than traditional glass, but some manufacturers will opt for just the front of the tank to be low-iron while the rest of the tank is traditional glass.  The most important place to have low-iron glass is on the front, so if you are considering the price, low-iron on the front of the tank only can achieve a good balance of cost and clarity.  Low-iron tanks also tend to come into play on larger tanks.  If you are considering a small tank (3 feet or less), the difference is likely going to be minimal between the two glass types. 

Low-Iron on the Left, Traditional Glass on the Right

Closing Remarks

I hope this guide was very useful to you.  Here at AquariumStoreDepot, we like to pass down knowledge to our customers.  A well-informed customer is a successful hobbyist and will enjoy this hobby for years to come.  If you are past these steps and looking into what livestock might work with your tank, check our Top 10 Best Saltwater Fish for Any Reef Tank post.  We would be happy to guide you on your journey to saltwater reefing!

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📘 Want to learn more? This article is part of our complete Saltwater Fish & Reef Guide. your ultimate resource for marine fish, coral care, reef setup, and more.