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I went back on forth on which tank to recommend for a cube shape, but ended with this one!

I ended up with the Waterbox Cube 20 with the optional Cabinet Stand.  This build is 20 gallons including the rear filtration chamber, and comes with a return pump, and the optional black/white stand.

But with a larger system comes a higher cost, and this is significantly more expensive than either the Budget Build or the Small Build.

If you want to save a few hundred dollars, just skip the stand.  But make sure you substitute some sort of table/stand that can support the weight of the Waterbox Cube 20.

Key Stats:

Size: 20 Gallons (76 Liters)

Approx. Price: $1,085

Dimensions: 17.7″L x 17.7″W x 15.8″H (45 x 45 x 40 centimeters)

Style: All-In-One Cube

Stand Included? Yes

Sump? No

Low Iron Glass? Yes, Starphire

Coming in at 20 gallons (76 liters) in total water volume, this low-iron (Starphire) glass tank pairs perfectly with the addition of the optional Waterbox Stand

The Cube 20+ comes with a WiFi LED light that can be programmed from your phone.  The rear filtration area comes with a filter sock, plastic bio balls, a sponge, and a return pump.

While this build does come with a higher price tag than either the Budget Build or the Small Build, It is up to double in size but still the AIO style which is simple for a beginner.

If you are craving a sump, check out some of the other builds!  But be prepared for a slightly steeper learning curve and a harder hit to your pocketbook!

The most important thing with this cabinet stand is to purchase the correct size!  The Waterbox Cube 20 requires the 18″ x “18” cabinet stand.

Currently these cabinets come in white or black. 

Relatively easy to assemble (the last one I put together took about 2-hours), these stands come with adjustable feet, soft-closing concealed hinges, and recessed push button(s).

This stand is expensive ($323-$400 at time of writing), so you could save some money by using something else.  Just be aware that this tank will weigh over 175 lbs (80 kgs) in water and glass!  So be sure that whatever surface you put this tank on, that it can support the weight.

The only thing I don’t like about this light (as of the writing of this article), is it doesn’t come with any presets!  So for a beginner, they might be quite confused!  How many hours a day?  What does acclimation mode mean? What intensity should I set each light at?

Not to worry.  Check out the Blueprints section on the Waterbox website.  Choose if you have a Fish Only, LPS, or SPS system, and you can download the proper settings!

Equipped with cool white, royal blue, blue, deep red, green, and uv led’s, you can program both for coral growth and color enhancement.  Plus, you just have to download the smartphone app and you can easily change settings from the couch!

But if for some reason you decide to buy this light separate from the tank, just remember that you also have to purchase the Prime Flex Arm to be able to mount it!

Here’s the thing about heaters: they all fail eventually, so keep that in mind.  There are several different types of heaters, primarily glass, ceramic, and titanium.  I’ve always used glass as they are inexpensive and heat the water quickly, but they are also easy to break (I’ve shattered at least two, maybe three!) 

These Eheim Jager heaters have been my go-to since the beginning.  I’ve never had one fail on me in over five years (with proper maintenance of course).  This heater does need to be calibrated, so be sure to pair it with a digital thermometer to narrow in on the temperature.

By the way, this 35-gallon tank requires the 100 Watt Jager!


CaribSea’s Life Rock comes in unique shapes, are sustainably made (not pulled from real reefs), and have a coralline algae colored surface which gives them that living reef look on day one.

Live Rock is important for a few reasons:  it provides a place for beneficial bacteria to colonize; it provides hiding places for your livestock; it gives you places to mount coral; and it is better than looking at an empty tank!

With  the size of this build, the 20lb box will likely be the perfect amount!

I own a couple different types of scrapers, but this Pro-Scraper II is my go to hand-held algae scraper (did I just use the word “scraper” four times in that sentence?).  You may have peeked to the next item and asked yourself, “why is My First Fish Tank recommending two algae scrapers?”  A valid question, and the answer is “convenience.”

If you just want one scraper, purchase this one, but rest assured that at some point in the near future you will long for the ease and simplicity of a magnetic scraper!

For this size tank, I think the 12″ would work, but you might want to go with the 16″-24″ adjustable so you don’t have to get your hands wet!

I’ve owned this Flipper for several years, and the fact that you can switch between the stainless steel blade and the soft felt side without getting your hands wet is just too convenient to pass up! 

Just make sure to get the regular Flipper.  The nano is too small and the max is too big!

For this build, I would probably go with the 9″ medium size.  If you get the mini it will suck up sand way too easily, but the large may drain the water a bit faster than you want.

A gravel vacuum is a must in this hobby for water changes.  It is the easiest way to start a siphon and drain your water, while at the same time vacuuming your sand bed free of detritus.

I probably have owned about 10 of these in the past several years, and they work well for how inexpensive they are.  I’ve tested three of these at a time in the same tank, and they were off by no more than 1.5 degrees F.  Not too bad considering!

A basic test kit is a must.  It is most important when you are starting your tank so you can test for when the nitrogen cycle is completed.  While not always the easiest to read, this test kit is affordable and will give a ballpark which will be good enough.  

Another nice thing about this build, is that it comes with a return pump!  If it doesn’t give you as much flow as you want, you can always upgrade it down the line to something with a higher flow rate.

Extremely inexpensive, every aquarium hobbyist needs a net!  Not only is it good for catching and transferring fish, you can also use it when thawing frozen food to help get rid of any fillers or phosphates!

It does need to be calibrated, but rather than buy an entire bottle of calibration fluid, just go to your LFS (Local Fish Store) and ask to use a few drops of theirs!

Buying an auto top off unit is not an absolute must for this build, but if you don’t, you will likely need to add 1/2 to 1 gallon of RO/DI water everyday by hand.  That gets to be a pain in the butt real quick, trust me on this!

This ATO unit from Reef Breeders comes with everything you need including the pump and silicone tubing. Just attach it to the last compartment of your sump, and put the pump in the ato reservoir, and it’s ready! You can forget about evaporation for at least a few days!

I own two of these, and they work great for the price.

Optional Items

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 your livestock plan.  

Most of us start out by buying saltwater at our LFS (local fish store), because purchasing distilled water from the grocery store is expensive, or buying the necessary RO/DI filter costs even more.

But you can save a bit of money and hassle in the long run by mixing your saltwater at home.

For this large build I recommend this salt, as it is good for FOWLR (Fish Only With Live Rock) systems, or tanks with a light stocking of corals.

Again not a necessity, but for around $35 you can control your tanks temperature to within 0.1° F.  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, you guessed it, “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.  Not bad for under $35!

If you are only planning on keeping fish in your saltwater aquarium, then you don’t need to worry about calcium and alkalinity.  But SPS (small polyp stony) and LPS (large polyp stony) corals, as well as invertebrates such as snails and crabs, need calcium and alkalinity to build their skeletons. 

Sand is not essential by any means, and there is a trend in the hobby toward a bare bottom tank.  That being said, sand does lend not only a nice aesthetic, but it aids in biological filtration, and provides a refuge and food source for certain creatures.

There are many types to choose from, but you would likely want a between 10-20 lbs for this build.  My favorites are the Arag-Alive Special Grade, Arag-Alive Fiji Pink, and the Arag-Alive Hawaiian Black.

I currently own four or five of these!  They are my inexpensive answer to an expensive controller.  I mount these either under my stand, or somewhere out of the way and then label each cord.  That way, whenever I need to do maintenance, I can just flip the individual switch to turn off the appropriate piece of gear.  I love these things and will keep recommending them well into the future!

Of course you don’t need to make your own RO/DI water.  You can either use distilled water (expensive), buy pre-made saltwater from your LFS (local fish store), or buy RO/DI water from your lfs.  But for under $200, you could skip all that and make your own water at home.  

An RO/DI filter was one of my first purchases because I refused to lug 5-gallon jugs back and forth from my LFS, and I didn’t want to buy gallon after gallon of distilled water.

I’ve owned my RO/DI filter for well over five years, and it is one of the best investments I’ve ever made.

A super quick note… don’t drink RO/DI water.  RO water is safe to drink, but RO/DI water is so pure that it may actually dehydrate you and suck nutrients from your body!  Just an FYI!

This may seem like a silly thing to add to a build list, but I have found that these two brushes do the brunt work of my cleaning.  They have a stiff bristle and have held up for me for many years now. They work much, much, much better than a toothbrush!

If you bought the RO/DI filter that I recommended in this build, you don’t need a TDS meter.  That’s because the RO/DI filter comes with an inline TDS meter already!

You could still get one because it’s kind of fun to test the TDS of different things!

Your goal when making saltwater is to have 0 TDS in the RO/DI water before adding salt. 

Just for reference, when I lived in Seattle the tap water had around 40 ppm TDS. I now live in Southern California and my TDS is 140 ppm.

My favorite utility pump is the Cobalt MJ1200, but for some reason (at the time of writing this), they are out of stock everywhere!  I’m thinking they had a production issue and are trying to catch back up with demand?

I’ve never actually owned this utility pump, but it’s made by the Italian company Sicce and I love their pumps!

I use my utility pumps to mix saltwater, pump RO/DI water into the reservoir, provide flow in my quarantine tank, and to clean my sump.  They are just so handy to have around that I own several and use them weekly.

While this is technically optional, if you plan on having fish (which I’m assuming you are), then this is a virtual necessity.

Fish jump!  Maybe they are spooked, maybe they are just playing around but regardless we don’t want them to jump out of their tank!

Little known fact about fish…they need water to breath!  Okay, you get the point.  

This kit comes with everything you need, including a clear mesh screen which is great because it let’s way more light though then your typical window screen.