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

Updated 2023

This Saltwater Aquarium Budget Build list is designed to help you set up a beautiful, high-tech, and versatile saltwater aquarium without breaking the bank or going for a huge setup! Even at this price point, you can take it step-by-step, buying one piece of gear with each paycheck. Our goal with this budget build is to strike the right balance between cost, aesthetics, and incorporating the latest gear. Additionally, we’ve ensured that this setup is as close to plug-and-play as possible, making it easy for you to set up and maintain your aquarium hassle-free!

One of my early tanks. Small, but stunning with some mid-range gear.

Size: 32.5 Gallon

Dimensions: 32.28 x 15.75 x 15.35 inches

Care Level: Easy

Style: Bowfront

Placement: Office, kitchen, living room, bedroom

The picture above is a great option from Fluval, but this one is slightly bigger… That means more fish and coral! And it comes with pump and light, which will save you quite a bit of money!

Check out the Fluval Sea Flex 32.5 US Gal. (123 L) Saltwater Aquarium Kit – it’s a cool addition to Fluval’s awesome curved aquarium series! The best part? It’s got a mobile device-operated Marine 3.0 LED that lets you customize the colors and effects. You can even set a 24-hour light timer – how cool is that?

This new Flex aquarium also comes with a built-in filtration system that keeps things super clean. It’s got two independent multi-stage chambers for maximum efficiency. You can easily fit in the Fluval PS1 skimmer, M150 heater, and there’s even a handy easy feed door for the Fluval PF2 Feeder. Plus, it comes complete with Foam, Carbon & Biomax filter rings. It’s a sweet deal for a slick saltwater setup!

Filtering a saltwater aquarium can indeed be a complex and perplexing aspect of the hobby, often leaving us unsure of how to proceed. However, experienced hobbyists will assure you that filtration can be simplified and made easy.

In basic terms, there are three types of filtration that work together to ensure the overall health of your saltwater aquarium:

1. Mechanical filtration
2. Biological filtration
3. Chemical filtration

The good news is that this saltwater aquarium comes with a starter kit of filter media, and it features a built-in filtration compartment seamlessly integrated into the aquarium.

These aquariums are known as AIO (all-in-one), with the filtration compartment incorporated within the tank itself, eliminating the need for additional filters. Moreover, if you decide to add any gear, such as a heater, you can discreetly hide it within this compartment, ensuring a clutter-free display in your saltwater aquarium.

If you prefer to opt for the highest quality filter media instead of the supplied items, we’ve listed what we believe to be the best options for the three types of filtration. Additionally, you’ll need a filter media bag, which you can easily find here.

Gravel Vacuum / Siphon

Apart from using filters and filtration media, another essential part of aquarium maintenance is water changes. It’s a straightforward process of removing some saltwater from your tank and replacing it with fresh saltwater. During this procedure, you can also use a siphon to “vacuum” and remove any detritus, such as fish waste and leftover food, from the tank.

To obtain saltwater, you can visit your local fish store and purchase it directly from them. Alternatively, you may find distilled water available at the fish store or your nearby grocery store. Distilled water is useful for topping off the aquarium because it helps maintain the salinity when water naturally evaporates. If you’re interested in making your own saltwater, we’ll cover that later on!

For this specific saltwater aquarium, I recommend getting the 9″ medium size siphon. The mini size drains water too slowly, while the large size drains the tank too quickly, making the medium size the ideal choice.


An essential piece of equipment for your saltwater aquarium is the heater. As mentioned earlier, stability is key to keeping your aquarium inhabitants happy, so a reliable heater is crucial.

Most saltwater aquariums house tropical organisms that thrive in a stable temperature range between 77-78 degrees Fahrenheit. Unless your house maintains that temperature consistently, you’ll need a heater to ensure the well-being of your aquatic friends. On the other hand, if you live in a very hot climate, you might require a fan to cool your aquarium instead.

Based on personal experience, reputation, and cost, we highly recommend the Eheim Jager TruTemp 100 Watt aquarium heater. It’s a favorite among many saltwater aquarium hobbyists and remains budget-friendly.

Keep in mind that all aquarium heaters will eventually fail, so it’s wise to have a backup plan. Consider getting a second heater as a spare for emergencies. One thing experienced saltwater aquarium hobbyists know is the value of having backup gear!


Thermometers play a vital role in a saltwater aquarium, as they help you ensure that your heater is maintaining the desired temperature. Often, heaters are not perfectly calibrated upon delivery, so having a thermometer allows you to re-calibrate and achieve the correct temperature.

Over the years, we’ve used about 10 of these thermometers, and they have proven to be effective despite their low cost. Even in the most budget-friendly builds, they are crucial equipment. In our tests, when using three of these thermometers simultaneously in the same tank, their readings differed by no more than 1.5 degrees Fahrenheit.

This product comes in a 2-pack because we’ve found it’s always a good idea to have an extra thermometer on hand. If you’re mixing your own saltwater, having an additional thermometer ensures consistent temperatures during the process.

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


A refractometer is an essential tool for every saltwater aquarium hobbyist. It offers superior accuracy compared to a hydrometer, making it a worthwhile investment even for those on a budget.

Maintaining stable and constant salinity levels is crucial for the well-being of corals and invertebrates like shrimp and crab. Unlike fish, these creatures are highly sensitive to sudden changes in water parameters, particularly salinity.

Keep in mind that a refractometer requires calibration for accurate readings. However, there’s no need to purchase an entire bottle of calibration fluid. Your Local Fish Store (LFS) will often be willing to lend you a few drops of theirs, making it a cost-effective and practical solution. Ensure the best environment for your saltwater inhabitants with the help of a reliable refractometer.

new refractometer out of package sitting on white background

Water Test Kit

Having a basic test kit is essential for any saltwater aquarium hobbyist. It proves most useful at the beginning of your aquarium journey, allowing you to test for the completion of the nitrogen cycle.

While this test kit may not be the absolute best on the market, it remains affordable and provides a ballpark reading that is suitable for most hobbyists. It serves as a valuable tool for monitoring your aquarium’s health and identifying any potential issues before they manifest as algae or bacteria blooms within the aquarium. Being proactive with testing can help you maintain a healthy and thriving saltwater aquarium.

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

Reef Rock

Rock plays a crucial role in every saltwater aquarium as it serves multiple purposes:

1. It provides a habitat for beneficial bacteria to thrive, aiding in the aquarium’s overall health.
2. The rock creates hiding spots for the aquarium inhabitants, giving them a sense of security.
3. It also acts as a surface for attaching coral, enhancing the beauty and diversity of your tank.

While there are various types of rock available, this particular option is both affordable and visually appealing, making it an excellent choice for a budget-friendly saltwater aquarium build. Embracing the importance of rock in your setup will contribute to the overall success and enjoyment of your aquatic world.

Saltwater Aquarium Reef Rock

Algae Scraper

Hey there, let’s talk about algae scrapers – a basic but essential tool for your saltwater aquarium. No matter how well you maintain your tank, algae will find its way onto the glass. The good news is that a cheap scraper can easily take care of it without making a mess of your arms!

Using the scraper to remove the algae and then siphoning it out helps with the filtration, keeping your aquarium cleaner. In our budget build, we went with a regular hand-held option, but you might want to upgrade to the Flipper magnetic algae scraper for even more convenience down the line. Happy cleaning!

Fish Net

Having a net is a must for every saltwater aquarium hobbyist, and the best part is that they are incredibly affordable! It’s one of those tools that you’ll find indispensable.

Not only is it handy for catching and transferring fish, but you can also use it while thawing frozen food to remove any fillers or phosphates. The net’s versatility makes it a valuable and practical tool to have on hand for various tasks in your aquarium.

black fish net with long handle on white background
Fish Net

Temperature Controller

Maintaining a stable temperature in your saltwater aquarium is crucial, as we previously discussed. Even the most reliable heating equipment can fail, leading to a complete aquarium crash. However, you can avoid such disasters with a simple and affordable solution priced at just $35. This device monitors your aquarium temperature, ensuring it stays within a precise 0.1° F range and prevents your heater from getting stuck in the “on” position, which could boil your saltwater.

The best part is that this controller can also handle cooling tasks! In my case, living in the desert, I use a fan during summers to keep my aquarium cool. I plug the fan into the “cooling” outlet and the heater into the “heating” outlet, maintaining a constant 78° F throughout the year. This impressive device also includes a built-in alarm, alerting me promptly if there’s a failure in the heater or fan. Remarkably, all these features come at an affordable price, making it an ideal addition to your budget-friendly aquarium build. With this controller, you can rest assured that your aquarium’s temperature remains stable, providing a safe and comfortable environment for your aquatic companions.

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


Sand might not be a must-have, and some hobbyists are opting for bare bottom tanks these days. But, adding sand can really transform your aquarium into an authentic slice of the ocean. It not only enhances the aesthetic but also plays a vital role in biological filtration. Plus, it becomes a cozy hideaway and a source of food for certain creatures.

When it comes to sand, we recommend sticking with the CaribSea brand for the best options. Happy decorating!

wet live sand for saltwater aquariums
Fiji pink sand in 20 lb bag with close up of grain size

RO/DI Water Filter

The RO/DI filter is a water filtration unit that transforms tap water into nearly pure water through the process of Reverse Osmosis Deionization. To understand its workings in detail, you can read this article.

While some online hobbyists might emphasize the necessity of an RO/DI filter for any saltwater aquarium, this claim isn’t entirely accurate. Although it offers long-term cost benefits and advantages, there are other simpler options for small and beginner saltwater aquariums.

One option is purchasing pre-made saltwater and purified water from your local fish store. Alternatively, you can use tap water conditioner along with tap water, but this approach carries some risks and may lead to issues with your saltwater.

However, if you’re ready to take the plunge, there is a small and affordable RO/DI filter option that works perfectly for this budget build and small saltwater aquarium. It offers a viable solution for those seeking an economical yet effective water purification system.

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

Many saltwater aquarium hobbyists initially opt to purchase ready-made saltwater from their Local Fish Store (LFS) due to the expense of buying distilled water from the grocery store and the complexities of setting up an RO/DI filter.

However, if you’re looking to save money and simplify your setup in the long run, mixing your saltwater at home is a viable option. With numerous salt mix varieties available on the market, I’ve personally tried many of them. While they all work well, their suitability depends on the specific inhabitants of your saltwater aquarium.

For this budget-friendly aquarium build, I recommend using this particular salt mix. It is ideal for Fish Only With Live Rock (FOWLR) systems or aquariums housing low-demanding corals. Embracing this salt mix will help you achieve a balanced and cost-effective saltwater solution for your aquarium needs.

Coral Pro Saltwater Aquarium Salt

Calcium / Alkalinity Test Kit

If your saltwater aquarium is primarily intended for fish or soft corals, you can relax about monitoring calcium and alkalinity levels. In such cases, regular water changes should provide the necessary nutrients and parameters these corals require.

However, if you plan to keep SPS (small polyp stony) and LPS (large polyp stony) corals, it’s crucial to maintain sufficient calcium and alkalinity levels to support their skeletal growth. This kit allows you to determine the ballpark values of these parameters in your saltwater, enabling you to gauge when additional dosing is required or if you may have been overdosing.

Maintaining proper parameters is essential for the health of your aquarium, even if you are diligently managing other aspects. By ensuring the right calcium and alkalinity levels for SPS and LPS corals, you create a thriving and balanced environment for these sensitive organisms to flourish.

Reef Tank test kit new in packaging on white background

Power Strips

One crucial piece of gear you might already have, or need to consider getting, is a power strip to accommodate all the equipment in your saltwater aquarium. While it may be tempting to cut corners here, it’s essential not to skimp on safety. Electrical accidents or fires are serious risks that should not be taken lightly.

Investing in a reliable surge protector/power strip is highly recommended. This particular option not only provides protection but also offers the convenience of turning off individual pieces of gear without having to unplug them. This feature is especially useful during saltwater changes, where it’s advisable to turn off the heater to prevent damage caused by exposure to air while still powered on. By choosing a quality power strip, you can safeguard your equipment, ensure the well-being of your aquatic animals, and create a secure and efficient setup for your saltwater aquarium.

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

Magnetic Algae Scraper

Among the items in this affordable budget build, the Flipper magnetic algae scraper stands out as an exception. While there are cheaper alternatives available, none can match the performance and durability that the Flipper offers. Personally, I have been using the same Flipper for several years, and it continues to work flawlessly.

One significant advantage of the Flipper is its versatility. It allows you to switch between the stainless steel blade and the soft felt side without getting your hands wet, a feature that any saltwater aquarium hobbyist will appreciate. This magnetic algae scraper not only ensures efficient cleaning but also provides convenience and ease of use, making it a valuable addition to your aquarium maintenance toolkit.

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