Updated 2025
It is definitely possible to set up a saltwater aquarium for under $500, and here’s how I 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.
This build wouldn’t be my #1 choice for a beginner, although it is a good one. If you are willing to spend $50 more, I highly recommend getting the HelloReef kit instead. It comes with way more, including 50+ step-by-step videos that I made.
What You'll Get For Under $500
Size: 10 Gallon (38 Liters)
Approximate Price: $500
Dimensions: 11.8″ L x 15″ W x 13″ H
Aquarium
Well this is the 3rd iteration of this build. Products keep going out of stock or changing, but for 2025, here is a great bundle from Innovative Marine. I don’t think I’ve owned this exact tank, but I have owned plenty of Innovative Marine tanks from their smaller 15 gallon nanos to their larger 40 gallon plus. The thing about this tank, is it’s small, but comes with great gear.
The tank is low iron glass, the mesh screen is preassembled and fits perfectly, I love the fact that it comes with both a filter sock and an acrylic media caddy. And it is amazing that at this price point, it comes with a near-silent DC powered controllable return pump.
This bundle currently costs $267, and comes with the following:
- 10 Gallon Aquarium
- MightyJet DC Return Pump
- Filter Sock
- Custom Media Caddy
- Mechanical Filter Balls
- 1 Pack Carbon
- 1 Pack GFO
- Preinstalled Rubber Leveling Mat
- Mesh Screen
- Magnetic Glass Cleaner
- Return Plumbing
You could definitely do a similar setup a little cheaper if you went with a standard 10-gallon tank from your local big box store and just put a hang on the back filter on it. But for the money, this setup is ideal because you get those clean lines and all of the gear will be hidden in the rear filtration chamber. But there will be a few other things you need to purchase.
Light
I used to use the AI Prime 16 as my go to beginner light… But ever since AI came out with this Blade, it takes the cake. For the price, this little light can grow anything. I’ve used it for well over a year now on my HelloReef tank, and it grows anemones like nothing I’ve used before. There are more affordable lights out there for sure, but those lights may not pack enough PAR in the right spectrum to grow coral.
And, the 12″ Blade comes with tank rests so you don’t have to purchase some sort of mounting system, it just sits nicely on top of the mesh screen included in the kit.

Filtration and Filter Media
You don’t need to buy anything here because the kit comes with all the filtration you need!
Gravel Vacuum / Siphon
Water changes for this saltwater aquarium build for under $500 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.
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!

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!

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.

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 $500 build.
CaribSea makes this 10lb box of reef rock. It looks great and is enough to get started.

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!

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 $500
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.
We also have an entire blog all about sand, so click here to check it out.
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.

Fish
While it’s a little premature to talk about fish, you’ll definitely want to start thinking about it. Check out our blog all about fish, including our top 10 beginner fish!
Here are a few of my current favorites! You can also click on the image to learn more!