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How to Setup a Cheap $300 Saltwater Aquarium - Budget Build Guide

Updated 2023

Discover the ultimate $300 budget-friendly Saltwater Aquarium Setup guide, designed to make aquarium ownership easy and affordable! Our focus is on providing you with the best prices for a functional yet inexpensive saltwater aquarium. Perfect for newcomers to the hobby, this guide offers valuable insights and hands-on learning experiences. Even those on a tight budget can dive into the world of aquarium keeping with this economical setup. We’re excited to share this useful guide with you! For those seeking more advanced options or looking to upgrade in the future, be sure to explore our other build guides available. Happy aquarium building!

Budget Build Stats:

Size: 10 Gallon (38 Liters)

Approximate Price: $300

Dimensions: 20.25 x 12.625 x 10.5 inch (51.4 x 32.1 x 26.7 cm)

Care Level: Easy

Style: Rectangle

Placement: Office, kitchen, living room, bedroom

A great example of a 4.8 gallon tank I made for BRS.


The cornerstone of this build guide is the saltwater aquarium itself, and we recommend starting with a simple 10-gallon rimmed tank from any big box pet store. These tanks are widely available and popular among hobbyists, especially beginners. 

 A 10 gallon saltwater aquarium is big enough to support a lot of beginner corals, fish, and invertebrates. At the same time, it is not so big that you need to spend a lot of time maintaining it, nor do you need to buy a dedicated stand for it. This aquarium could easily fit on a strong desk, table, or even kitchen counter! 

With this sizeable tank, you have the opportunity to be creative with your aquascape (also known as the rock structure). The rock structure is of paramount importance in your saltwater aquarium, serving as the foundation for coral attachment and providing a sanctuary for your fish.

Once you purchase and receive the tank, it’s essential to place it on a flat and waterproof surface (such as outdoors, a balcony, or a flat bathtub) and fill it up with tap water. There’s always a chance of damage that might go unnoticed. Allow the aquarium to sit in a safe location filled with water for approximately 24 hours. During this time, if you detect any damage or leaks, make sure to get a replacement promptly. Safety and precaution are crucial for a successful saltwater aquarium setup!

10 gallon cheap glass aquarium
Rimmed 10g Aquarium


This light is nothing fancy.  Affordable, and will put off enough light to grow soft corals, although I wouldn’t try to grow much more than that.  An absolutely great light for a fish only tank though!

The ClassicLED Marine LED aquarium light offers a new saltwater lighting option from NICREW. It combines white, 445nm blue, 460nm blue, and RGB LEDs to create a natural lighting effect for your fish tanks. With its dual-channel timer, you can easily adjust the intensity and set ramp effects for different channels. The fixture has adjustable legs to fit various aquarium lengths and features a durable aluminum alloy shell.

The light offers three lighting modes and is designed to provide 8-10 hours of recommended lighting time. It operates with a super safe 20V DC fixture for aquarium use and is compatible with the Nicrew dual-channel LED timer, which is included in the package.

Filtration and Filter Media

Filtering a saltwater aquarium may seem complicated, but it doesn’t have to be! Let’s break it down without getting too technical. There are three types of filtration that work together to keep your aquarium clean:

1. Mechanical filtration: This removes physical debris and particles from the water. It’s like a basic strainer that catches larger debris.

2. Biological filtration: This involves beneficial bacteria that break down harmful substances, like ammonia and nitrite, into less harmful ones.

3. Chemical filtration: This uses chemical substances, like activated carbon, to remove impurities and toxins from the water.

Now, for your aquarium, you’ll need a Hang-on-Back (HOB) filter that hangs on the side. These filters are common, affordable, and easy to use. We’ve listed the best options for filter media to cover the three types of filtration. Don’t forget to grab a filter media bag to keep everything tidy.

For added flow and improved filtration, consider getting a second filter. Doubling up on filtration can be beneficial for your tank’s health.

Hang On Back aquarium filter for saltwater aquarium
Aquaclear HOB Filter

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 50 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!

Aquarium Heater Eheim Jager
Aquarium Heater Eheim-Jager-TruTemp-50-Watt-Fully-Submersible-UL-Approved-Heater


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 a handy tool used by saltwater aquarium hobbyists to gauge the salinity of their aquarium water. They are highly accurate and over the years, instead of going up, the price just keeps coming down.

Easy to use, and probably the most accurate way to test your salinity!


In a saltwater aquarium, rock plays a crucial role as it provides:

1. A habitat for beneficial bacteria to thrive.
2. Hiding spots and shelters for the aquarium inhabitants.
3. A surface to attach coral.

To grasp the significance of rock in a saltwater aquarium, I recommend watching this video. Among various types of rock available, this particular one is not only cost-effective but also visually appealing, making it a perfect fit for a budget-friendly saltwater aquarium build.

pile of dried out porous rock made from dead coral skeletons

Algae Scraper

An algae scraper is a straightforward and practical tool for your saltwater aquarium. Despite maintaining your tank diligently, algae will inevitably grow on the glass. This inexpensive scraper is the simplest way to remove the algae without getting your arms wet and messy! Additionally, when you siphon out the scraped-off algae, you contribute to the filtration process in your saltwater aquarium.

For this budget-friendly saltwater build, we opted for a user-friendly hand-held option. However, as you progress, you might consider getting the Flipper magnetic algae scraper for even greater convenience!

Fish Net

A net is an essential tool for every saltwater aquarium hobbyist, and the best part is they are incredibly affordable! Having a net is a must-have in your arsenal.

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. A net’s versatility makes it even more valuable for your aquarium needs!

black fish net with long handle on white background
Fish Net

Optional Items

Water Test Kit

A basic test kit is a highly useful tool for any saltwater aquarium hobbyist. It proves especially valuable at the beginning of your aquarium journey when you need to monitor the completion of the nitrogen cycle. Although it’s possible to set up the aquarium correctly without a test kit, having one will provide you with more accurate information.

Here’s a simple method to start your aquarium: set it up, add your rock and sand, and fill it with water. Turn on all your equipment, except for the lights. Drop in a sizable piece of shrimp from the grocery store, let it decompose, and wait for about a month or two for the cycle to complete.

Nevertheless, having a test kit on hand wouldn’t hurt! While this test kit may not be the absolute best available, it is affordable and will provide you with a ballpark reading, which should suffice for most hobbyists. It’s also a useful tool for monitoring your aquarium’s health and identifying any issues before they manifest as algae or bacteria blooms within the aquarium.

front view of api saltwater test kit in original packaging


While sand is not a necessary component, it holds a special appeal in the saltwater aquarium hobby, with some enthusiasts opting for a bare bottom tank. However, incorporating sand into your setup adds a touch of authenticity, making your aquarium feel like a slice of the ocean. Besides its aesthetic benefits, sand plays a role in biological filtration and serves as a refuge and food source for certain creatures.

If you’re considering adding sand, watching this video will provide you with valuable insights to help you make an informed decision!

For this aquarium, you’ll only need a 10 lb bag of sand. While various types of sand are available, we recommend sticking with the CaribSea brand for its reliability and quality.

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

Salt Mix

Many saltwater aquarium hobbyists initially purchase saltwater from their Local Fish Store (LFS) because buying distilled water from the grocery store can be costly, and setting up an RO/DI filter can be complicated.

However, if you want to save money and avoid long-term hassle, mixing your own saltwater at home is a great option. For this budget-friendly aquarium build, we recommend using this salt mix, which works well for FOWLR (Fish Only With Live Rock) systems or aquariums with low-demanding corals. It’s one of the most trusted and widely used salt mixes available, having been in the market for quite some time.

Power Strips

A crucial piece of equipment for your saltwater aquarium setup is a power strip, which you might already have. However, if you haven’t realized it yet, you’ll definitely need one to accommodate all the gear. It’s essential not to compromise on the quality of the power strip, as electrical accidents or fires are serious concerns. Cheaping out on this can lead to potential harm to your animals or even cause irreparable damage to your gear and spark a fire.

For safety and convenience, we recommend investing in this surge protector/power strip. It not only offers surge protection but also allows you to individually turn off pieces of equipment without unplugging them. This feature proves especially useful during saltwater changes, as you can safely turn off the heater to prevent damage while exposed to air.

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