Peninsula Build List

The goal of this build is to give you a top-of-the-line saltwater aquarium, perfect for a good amount of livestock, capable of maintaining LPS and SPS corals, all in a desirable peninsula shape!

I’ve chosen a 20 gallon (76 liter) peninsula style aquarium from Innovative Marine.  It is small enough that you could place it on a sturdy desk, but the peninsula style gives you three large viewing areas which really maximizes every angle.

The Pro Bundle is handy because it comes with filter sock, media basket, return pump, self-leveling mat, and pre-made mesh screen! 

Key Stats:

Size: 20 Gallons (76 Liters)

Approx. Price: $775

Dimensions: 11.8″L x 30″W x 13″H (30 x 76 x 33 centimeters)

Style: Desktop Peninsula w/Rear Filtration Chamber

Stand Included? No

Sump? No

Low Iron Glass? Yes

This 20-gallon peninsula tank comes with some pretty good stats:

You get the picture.  This build will weigh over 150 lbs in water alone, so if you don’t have a sturdy desk or counter, consider buying the stand below.

This Innovative Marine Stand is meant to pair perfectly with the 20-gallon peninsula tank.  But the great thing about the 20-gallon size is that if you have a sturdy desk or countertop, you probably don’t need it.  

But it is nice to have a stand for many reasons, including a great place to hide your maintenance gear!

I thought long and hard about which light to recommend, and really went back and forth between a long fixture that would span the entire length of the tank, vs. this single square fixture that I ended up with.

The reason I decided to go with this Aqua Illumination 16 Prime HD LED Light w/ Flexible Mounting Arm was purely aesthetics.  The stunning thing about a peninsula style tank is it almost appears to be all tank.  A long, bulky LED fixture would just muck that up.

The only word of caution here is to know that the flex-arm will likely not span all the way to the center of the tank if you mount it from the back.  So you can either just be okay with that, or purchase the ceiling mounting kit instead!

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 20-gallon tank requires the 75 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 I would buy 20 lbs of the Life Rock Shapes (left).  You will get about four distinct pieces.

But if you are worried that you might want some more flexibility, then just go ahead and buy 20 lbs of the Life Rock (right).

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 build, I think the 12″ would work just fine, considering the total height of the tank is only 13″.

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 to easily, and if you go with the large, it will drain the tank too quickly!

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!

If the heater you purchased already came with one of these, then you can skip buying this 2-pack.  But I’ve found it is never a bad idea to have an extra thermometer (or two) on hand!

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.  

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!

I’ve also heard you can use a few drops of distilled water to calibrate, but I’m not sure if that is as accurate!

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 budget 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 only need 10-20 lbs for this build.  My favorites are the Arag-Alive Special Grade, Arag-Alive Fiji Pink, and the Arag-Alive Hawaiian Black.

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!

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.

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  gallon of RO/DI water everyday by hand.  That gets to be a pain in the butt real quick, trust me on this!

I own the the fancier Tunze Osmolator, which has both a float switch and optical eye.  It costs quite a bit more, but mine has never failed me in over five years, with the original pump!

This Osmolator Nano is the perfect size for this 20-gallon build.  Just put the pump in a five-gallon bucket and you won’t have to worry about evaporated water for a week!