a small rimless saltwater aquarium with white sand and white rock inside. Two orange clownfish are swimming, and the tank has a hang on the back filter and small led light attached. The aquarium is sitting on a grey wood table with a blurred bright bedroom in the background

How To Set Up A Saltwater Aquarium For Under $300

Updated 2024. It is definitely possible to set up a saltwater aquarium for under $300, and here is how we would do it.

In this guide we strictly focus on the best prices for the cheapest (but functional) saltwater aquarium. This is a good build for someone who is new to the saltwater aquarium hobby, and wants to learn from experience!

As well, anyone who is on a tight budget can use this cheap build guide to start an aquarium. We hope you find this guide useful! If you are looking for something fancier, or to just upgrade from this build, check out our other build guides here

What You'll Get For Under $300

Size: 10 Gallon (38 Liters)

Approximate Price: $220

(Total with all optional items: $300)

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

Optional Items

Aquarium

This original setup for a saltwater aquarium under $300 had a standard 10 gallon tank with a black plastic rim that you could pick up for cheap at your local big box pet store.  But, For just a little bit more, you could build a really slick looking rimless tank, and it just so happens that Bulk Reef Supply has a great kit.

a product picture of a saltwater aquarium bundle containing a small rimless rectangular glass tank, black hang on the back filter, bag of sand, four pieces or white rock, an led light, and glass heater

This bundle currently costs $200, and comes with the following:

  • 9.6 Gallon AquaMaxx Rectangular Rimless Aquarium
  • 50W Eheim Jager Heater
  • AquaMaxx Prism CC II LED Light (Marine)
  • Seachem Tidal 35 HOB Power Filter
  • 8lbs MarcoRocks Reef Saver Aquarium Dry Rock
  • 10lbs CaribSea Fiji Pink Arag-Alive! Reef Sand

You could probably save a little bit more money by building this kit yourself if you swapped out the rimless tank for one of those big-box store tanks.  And if you swapped out the Seachem Tidal HOB filter for something cheaper from Amazon.  Penn Plax makes some inexpensive filters.

Light

I’ve never used this light.  It’s super small and inexpensive, and it actually comes with a timer so you can create a schedule.  I’m not sure how long this light will be around for, as everything in the Aquamaxx brand (Marine Depot’s brand), is being converted, improved, and expanded into the new AquaReady brand (Aperture Brand).  But I’m guessing that even if the name or brand changes, that this light will still exist.

It’s perfect for this small system.  Just clips on the side, has a timer, and the marine version has a good spectrum for coral growth

Now don’t go thinking that you can grow high light demanding coral with this light… You can’t.  But this light would work for some softies and even some LPS corals.  If you get the entire kit, then obviously don’t buy this light as it’s included.

product picture of small strip led light. The lights are multicolored and attached to a stainless steel looking curved mount

Filtration and Filter Media

For an entire saltwater aquarium build for under $300, The Seachem Tidal filter is more expensive, but comes with one feature the others don’t… a surface skimmer.  Now I’ve owned this, and I can’t say the surface skimmer works super great at removing film from the surface, but it’s better than nothing. And Seachem is a known brand with customer service.  If you go with the kit, the Tidal filter is what you’ll get.

But if you build this kit yourself, then the cheaper option is the Penn-Plax 20.  Nothing fancy, just a power filter that you can put some sort of sponge or filter floss into.

a black hand on the back power filter with blue accents
Seachem Tidal HOB Filter
a blue hang on the back power filter with a black lid
Penn-Plax Cascade Power Filter

Gravel Vacuum / Siphon

Water changes for this saltwater aquarium build for under $300 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. 

If you are wondering where to get saltwater, go to your local fish store and directly buy it from them! You may also want to buy distilled or RO (filtered) water from them or a grocery store. We use this water for topping off the aquarium because when water naturally evaporates, you want to add pure, fresh-water to maintain the salinity in the saltwater aquarium. If you want to make your own saltwater, we’ll put a video below

For this saltwater aquarium, I suggest buying the 2″ medium size. 

Python 2" Gravel Vacuum on a white background

Heater

 A simple but very important piece of equipment is your heater! As was mentioned before, you 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 77-79 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 50 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!

This kit already comes with one, so you could just pick up one extra!

Aquarium Heater Eheim Jager attached to suction cup base on a white background

Thermometer

Thermometers are very important in a saltwater aquarium, because you need to confirm that your heater 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. 

I think this is the cheapest thermometer you can get, and it works like a charm.  I’m using one on my HelloReef tank, and it’s super easy to just give it a quick glance to make sure the water temperature is just right!

A small stick on aquarium heater in cardboard packaging.

Refractometer

A refractometer measures the salinity of water.  If you only get one piece of testing gear, this is the one you absolutely can’t go without.  They usually come pre-calibrated, but this BRS version comes with calibration fluid which is nice so you can be sure it’s calibrated just right.

The exterior grey plastic case for a saltwater aquarium refractometer and a small bottle of calibration fluid sitting next to it.

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 this under $300 build.

This kit does come with rock, but if you want to build your own kit and want to explore some coralline purple colored rock, check out the link below.

Three pieces of human made coralline colored rock against a white background

Algae Scraper

Obviously you will need an algae scraper. My absolute favorite is the Flipper (you would need the Flipper Nano for this size tank).  But that costs a bit more money.  All you really need is an old credit card or library card.  Seriously, they work great.  Or you can buy a pack of cards like the one below from Flipper, but they give you so many it will last you like 40 years!

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!

three different sized aquarium fish nets next to each other on a white background

Optional Items

Water Test Kit

A basic test kit is a very useful 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. However, you do not really need it, provided you set up the aquarium correctly. Set up the saltwater aquarium, add your rock and sand, and fill it up. Turn on all your gear, except your lights. Throw in a big piece of shrimp from the grocery store to decompose and wait a month or two while the cycle completes! 

Still, it would not be a bad idea to get a test kit! 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. 

Sand For Saltwater Aquarium Under $300

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 makes your aquarium really feel like its a slice of the Ocean. As well, sand aids in biological filtrationwhile 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!

Again, if you buy the kit, it comes with 10lbs of sand which is the perfect amount.  But if you want my top three options for this tank, check out the links below.

wet live sand for saltwater aquariums close up shot of 10 pound bag
Special Grade
Fiji pink sand in 20 lb bag with close up of grain size
Fiji Pink
clear bag of aquarium sand with CaribSea label and close up of grain size.
Original Grade

Salt Mix

Most saltwater aquarium hobbyists start out by buying saltwater at our LFS (local fish store), because purchasing distilled/filtered RO 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. 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. It is probably the most trusted and used salt mix out there, as its been available for quite some time. 

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