How to Setup a $700 Saltwater Aquarium
-Budget Build Guide

Updated September 2020

By Maxim B.

This $700 Saltwater Aquarium Budget Build list is made to show you how to setup a beautiful, high tech, and versatile saltwater aquarium. However, we don’t want you spending a fortune or setting up a huge aquarium! Even at this price, it is often smart to just buy one piece of gear with each paycheck! We made this budget build list to find a balance between costs, looks, and the newest gear. As well, this budget build is as close to plug-and-play as possible so that it is easy for you to setup and maintain!

20 gallon saltwater aquarium with cora
@betos_nano_reef on Instagram 20g Waterbox Saltwater Aquarium

Table of Contents

(click on a topic to head directly to that section)

We ordered the list in importance and in the order in which we believe it is best to buy gear.

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Budget Build Stats:

Size: 20 Gallon (75 Liters)

Approximate Price: $700 

(With optional items: $1100)

Dimensions: 17.7 x 17.7 x 15.8 inch (50 x 50 x 40.1 cm)

Care Level: Easy

Style: Cube

Placement: Office, kitchen, living room, bedroom

Aquarium

The first and most defining piece of gear in your saltwater aquarium build is the aquarium itself. The aquarium’s size, shape, and filtration system will be what decides what you keep inside your aquarium. As well, it decides what other gear you should get!

However, it is not so big that you need to spend a ton of money on extra gear, spend a lot of time maintaining it, and you do not even need to buy a dedicated stand for it. An aquarium this size could fit on a strong desk, table, or even kitchen counter.

A cube aquarium will let you create an aquascape (AKA, rock structure) with depth that makes the aquarium look bigger than it is. As an added bonus, this aquarium is made of extremely clear “Starphire Glass” which has better visibility than normal glass. If you want to learn more about aquascaping, check out this article by Reefbum. The rock structure of your saltwater aquarium is very important as it is where you will attach your corals, and it is key to the looks of your aquarium. 

Finally, once you buy and receive the tank, make sure to put it somewhere flat and waterproof (outdoors, balcony, flat bathtub, etc.) and fill it up with tap water. During shipping of aquariums, there is always a chance they will be damaged and you might not even see it. Let the aquarium sit somewhere safe for about 24 hours filled with water, and if it is damaged or leaking, get a replacement! 

Filtration and Filter Media

Saltwater aquarium filtration can be the most complicated and confusing part of the aquarium hobby. How to filter an aquarium and what filter media to use is usually the last thing we fully understand as hobbyists. However, an experienced hobbyist will tell you that filtration really can be easy and simple.

And so, without getting scientific, there are three types of filtration that work together to complete the total filtration of your saltwater aquarium. These types of filtration are:

  • Mechanical filtration
  • Biological filtration
  • Chemical filtration

I HIGHLY suggest that you watch the following video for an in-depth explanation on how filtration works, as it would require a whole separate article for me to explain it here. 

But, there is good news! This saltwater aquarium already comes with a starter kit of filter media, and has a built in filtration compartment that is nicely tucked into the aquarium.

These kinds of aquariums are called AIO (all-in-one) as the filtration compartment is within the aquarium itself, so you do not need to buy any extra filters! As well, if/when you add gear (such as a heater) you can hide it within this compartment so that it does not clutter up the display portion of your saltwater aquarium! 

If you decide that you want to get the highest quality filter media instead of the things that come with the aquarium, we have listed what we think are the best options for the three types of filtration! Also, you will need a filter media bag to put it in, you can buy that here.

Poly Filter Floss
MarinePure-High-Performance-Biofilter-Media-1.5-inch-Spheres-2-Quart-99
Chemi-Pure Blue chemical filtration in nano packets for saltwater aquarium
Chemi-Pure Blue nano 5-pack for chemical filtration of aquarium

Gravel Vacuum / Siphon

There is another part to aquarium filtration that does not include filters and filtration media, and that is literally changing the water in your tank! Water changes are as simple as removing some saltwater and adding fresh saltwater to your aquarium. During this process, you can also use the siphon to “vacuum” by sucking up any detritus, which consists of fish waste, leftover food, or other nastiness in your saltwater aquarium. 

For this saltwater aquarium, I suggest buying the 5″ medium size.  If you get the mini it will drain water too slowly while the large will drain the tank too quickly! This piece of equipment is pretty universal, cheap budget build or expensive build, the only thing that changes is the size. 

Heater

Heating your saltwater aquarium is a truly simple task. There are a few types of heaters, but generally, you just want a heater that is reliable and heats to the temperature you need. As was mentioned before, your saltwater aquarium prefers stability to be happy, so you should not have to mess around with your heaters often.

Most saltwater aquariums house tropical organisms that need a stable temperature between 77-82 degrees Fahrenheit. Unless your house is constantly in that temperature range, you will need a heater to keep you aquarium inhabitants healthy and happy. In the case you do live in a really hot climate, you may need to get a fan to actually cool your aquarium instead! 

Based on personal experience, reputation, and cost we recommend the Eheim Jager TruTemp 100 Watt aquarium heater. It is a favorite of many saltwater aquarium hobbyists, and has always remained affordable!

The thing about aquarium heaters is that they all fail eventually, so keep that in mind. It would be a good idea to eventually have two heaters, with the second being a spare for emergencies. The one thing all saltwater aquarium hobbyists realize, is that it always good to have back up gear!

Aquarium Heater Eheim Jager

Thermometer

The thermometers are very important in a saltwater aquarium, because you need to confirm that your heater is keeping your aquarium at the temperature you chose! It is normal for heaters to not be properly calibrated upon delivery, so you need to have a thermometer to re-calibrate and make sure you have the correct temperature. 

We have owned about 10 of these thermometers in the past several years, and they work well for how inexpensive they are. Crucial equipment in even the cheapest of budget builds. We tested three of these at a time in the same tank, and they were off by no more than 1.5 degrees Fahrenheit!

This is a 2-pack because we found it is never a bad idea to have an extra thermometer on hand! If you are mixing your own saltwater, you will need an extra thermometer to make sure the temperatures are consistent. 

two small waterproof digital aquarium thermometers on white background
Digital Thermometer Two Pack

Refractometer

Every saltwater aquarium hobbyist needs a refractometer. This is because a refractometer is way more accurate than a hydrometer. Even if you are committed to the cheap budget build, this is a good investment.

Keeping your saltwater salinity at a stable and constant level is important when keeping corals or animals like shrimp and crab. Unlike fish, invertebrates are much more sensitive to drastic changes in water parameters like salinity. 

It is important to know that a refractometer does need to be calibrated. But, rather than buying an entire bottle of calibration fluid, just go to your LFS (Local Fish Store) and ask to use a few drops of theirs!

new refractometer out of package sitting on white background

Water Test Kit

A basic test kit is a must have tool for a saltwater aquarium hobbyist. It is most useful at the start of your aquarium, so you can test for when the nitrogen cycle is complete. 

This test kit is not the best available, but it is affordable and will give a ballpark reading, which will be good enough for most hobbyists. You can also use this to keep track of your aquarium’s health and to find out the cause of some issues before they manifest in the aquarium itself as algae or bacteria blooms. 

front view of api saltwater test kit in original packaging
API-Saltwater-Liquid-Master-Test-Kit-99

Reef Rock

Rock is very important in any saltwater aquarium as it provides: 

  • A place for beneficial bacteria to live
  • Hiding spots for your aquarium inhabitants
  • A place to attach coral.

To understand the importance of rock in a saltwater aquarium, watch this video. There are many types of rock, but this rock is cheap, looks great, and is perfect for a cheap saltwater aquarium budget build. 

Saltwater Aquarium Reef Rock

Algae Scraper

An algae scraper is a simple and self-explanatory piece of equipment. Even with a perfect maintenance routine for your saltwater aquarium, algae will grow on your aquarium glass. The cheap scraper is the easiest way to remove the algae without getting your arms wet and messy! As well, when you siphon out the algae you scrape off, you are aiding the filtration of your saltwater aquarium.

We went for the common hand-held option in this saltwater budget build, but you may eventually want to also get the Flipper magnetic algae scraper to make your life even easier!

Fish Net

Every saltwater aquarium hobbyist needs a net, and they cost almost nothing! A net is just one of those tools that you always want to have.

Along with being good for catching and transferring fish, you can also use it when thawing frozen food to help get rid of any fillers or phosphates!

black fish net with long handle on white background
Fish Net

Temperature Controller

We previously established how important a stable temperature for your saltwater aquarium is. We also know that heating equipment can sometimes fail, no matter how reliable it is, and this type of failure can cause the complete crash of your saltwater aquarium. For just $35 you can control your aquarium’s temperature to within 0.1° F. This device just monitors your aquarium temperature, and makes sure that your heater does not get stuck in the “on” position, boiling your saltwater.

It actually has the ability to make sure you aquarium gets cooled too! I live in the desert, so in the summer I run a fan to keep my aquarium cool. I plug my fan into the “cooling” outlet and my heater into the “heating” outlet, and my tank stays a constant 78° F all year round.  Plus, this controller has a built in alarm which alerts me if my heater or fan ever fail. Quite amazing for a $35 device and it still fits within the cheap budget build!

black and grey temperature controller with probe sitting on white surface
Bayite 10 Amp Temperature Controller

Sand

Sand is not essential by any means. There is even a trend in the saltwater aquarium hobby being a bare bottom tank. That being said, sand completes a genuine aesthetic to make your aquarium really feel like its a slice of the Ocean. As well, sand aids in biological filtration while providing a refuge and food source for certain creatures. This video is good to watch if you want to learn more before you make a decision! There are many types of sand to choose from but we would stick with the CaribSea brand.

wet live sand for saltwater aquariums
Caribsea-Arag-Alive-Special-Grade-Reef-Sand-10-lb-99
Fiji pink sand in 20 lb bag with close up of grain size
CaribSea-Arag-Alive-Fiji-Pink-Sand-10-lbs-99
hawaiian black sand in 20 lb bag with close up of grain size
CaribSea-Arag-Alive-Hawaiian-Black-Sand-20-lb-99

RO/DI Water Filter

The RO/DI filter is a water filtration unit that takes your tap water and purifies it to be as close to pure water as possible. It stands for Reverse Osmosis Deionization, and if you would like to understand how it works, read this article

You might hear from hobbyists online that an RO/DI filter is a must for any saltwater aquarium, but that just is not true. It does have benefits, and is mathematically cheaper in the long run. But, for small and beginner saltwater aquariums, there are other options that can be easier and simpler. Still, for this system, it will certainly be worth it to get an RO/DI filter!   

If you want to go ahead and take the plunge, there is a small and cheap option available, which will work perfectly for this cheap budget build and small saltwater aquarium. 

RODI filter from Aquatic Life with 4 cylinders for saltwater aquariums
AquaticLife RO Buddie Four Stage RODI system with DI included

Optional Items

Salt Mix

Most saltwater aquarium hobbyists start out by buying saltwater at our LFS (local fish store), because purchasing distilled water from the grocery store is expensive, and setting up the necessary RO/DI filter can be complicated

But, you can save a bit of money and hassle in the long run by mixing your saltwater at home. There are so many different types of salt mix on the market, and I’ve tried a ton of them!  They all work fine, but they vary depending on what you plan to keep inside your saltwater aquarium.

For this aquarium budget build we recommend this salt mix, as it is good for FOWLR (Fish Only With Live Rock) systems, or aquariums with low-demanding corals.

Calcium / Alkalinity Test Kit

If you are only planning on keeping fish or soft corals in your saltwater aquarium, then you don’t need to worry about things like calcium and alkalinity. This is because you water changes alone will likely provide all the proper nutrients and parameters that these corals need. 

But, SPS (small polyp stony) and LPS (large polyp stony) corals, need enough calcium and alkalinity to build their skeletons. This kit will let you know the ballpark values of these parameters in your saltwater. Thus, you know when you might need to dose extra or when you may have been over-dosing. This is very important, as your aquarium will suffer without proper parameters, even if you are doing everything else correctly.  

Reef Tank test kit new in packaging on white background

Power Strips

This is a piece of gear that you potentially already own, but if you have not realized it already, you will need a power strip to accommodate all the gear of your saltwater aquarium. This is not somewhere you want to be cheap, as the dangers of electrical accidents or fires should not be taken lightly. At best, your gear will turn off and your animals may get harmed. At worst, your gear will be destroyed and a fire might start!

We suggest getting this surge protector/power strip because it also has the ability to turn off individual pieces of gear without having to unplug them. This is very useful for saltwater changes, when it is recommended to turn off the heater so it does not get exposed to air while on and damaged.

7 outlet controllable surge protector and power strip
Tripp Lite 7 Outlet (controllable) surgeprotector powerstrip

Magnetic Algae Scraper

This is one item in the cheap budget build that is not a budget item! While there are cheaper magnetic algae scrapers, none of them even come close to what the Flipper offers. I’ve owned the same one for several years and it still works great!  You can also alternate the stainless steel blade and the soft felt side without getting your hands wet, which is a benefit to any saltwater aquarium hobbyist.

Flipper nano Algae Scraper out of packaging on white background
Flipper Nano 2-in-1 Magnetic Algae Scraper for Aquarium Glass or Acrylic

Conclusion

This is the end of how to build a $700 saltwater aquarium budget build guide! We provided you all the necessary items in order of importance, and even some optional items that would improve your saltwater hobby experience. We hope that you found this article helpful and informative, and if you decide to buy anything, please use our provided links! This costs you nothing extra, but helps us keep working, supporting you, and making great content. Feel free to look around the website or YouTube channel  if you have any questions about the hobby!

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