The Nantucket: a 2 Gallon Reef Tank




Introduction: The Nantucket: a 2 Gallon Reef Tank

About: born and raised a California native. I do QA for the development team here at Instructables.

There is a place known as Nantucket, it is an island 30 miles south of Cape Cod...

There is a new contender for the title, a reef tank known as Nantucket! It is a ~2gal marine reef habitat created by and for the QA department here at instructables. Here is what it looked like on the store shelf:

Not much of a fish tank at first sight... but we will find it quite capable given enough time and energy poured into it.

Of note here is that this was a budget build at heart, with the goal of having a stocked miniature reef for less than I paid for just the glass enclosure that was my first reef tank some years ago: 14gal biocube

As a personal goal, seeing as I've had to rent trucks and u-hauls in the past to move my fish tanks, this tank and all of it's applicable pieces were purchased with just a trusty oversized backpack and a similar skateboard. One trip for everything that wasn't live. 2 trips for everything that was live, from rocks and sand to coral frags and livestock.

Teacher Notes

Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.

Step 1: The Confirmation of Faith

A series of thoughts have led myself, the creator, down into the depths of Internet Forums of crowdsourced opinions and experiences. Research into the minuscule world of "Nano Reef's" has led me to believe my flame of desire was indeed a reality.

Here is one that really set me on the Creation path

Or a more pre-packaged version such as this

Invigorated by this confirmation of my faith, I set out to make a Marine environment on a Pico scale.

Step 2: Let There Be Light

I, the Creator, found a LED actnic light of high intensity that would screw into a ordinary light socket.

This opened the door for opportunity in limitless light fixture possibilities. I placed the order and awaited my shipment impatiently.

It would seem that the online retailer I purchased this light from has stopped selling this model, so I can't link to what I purchased. but here are some details from a teardown done by For such a small tank we really can't have any high heat lighting like a HQI or metal Hallide light fixture, just keep in mind that coral require the 10000K "actnic lighting" but most folks prefer a mix of 10000K actnic lighting and 14000K pure white to balance out the blue hue of Actnic lighting.

Meanwhile, I went to my local Ace Hardware, and purchased a simple light socket fixture and a timer. I prefer the longer length of cord and smooth ceramic socket compared to the average black plastic with metal hat "chicken light".

But really there will be a separate instructable on how to make a stand for the lights. stay tuned, As i will also be adding white LED's and moonlights to give a full spectrum of light for my creation.

light bulb was $40

light socket was $10

timer was $20

Step 3: Acquisition of Raw Materials

I acquired an awesome 2Gal glass pot with lid and drilled spout from my local Marshals for $20

I went to my local fish store and purchased the following:

  • 1 tiny airpump
  • air line tubing (clear)
  • 5lb bag of fine grain white sand
  • tiny hydor submersible powerhead
  • smallest box of marine salt mix
  • 2 air stones

All together I have the following materials to create my minuscule eco-system:

  1. LED Actnic 10000K lamp bulb
  2. ordinary ceramic lamp fixture with clamp
  3. 1 box of marine grade salt (makes 10gallons of saltwater)
  4. 1 sumbersable powerhead
  5. 2 airstones
  6. 15ft of clear air tubing
  7. a 2gal jar for the tank
  8. Air Pump
  9. 5lbs of fine grain white sand

My total here is $110

With the $70 from the light setup, I'm at $180 total investment.

Step 4: Build Day

Now that we have everything in hand, let the modifications begin!

Preparing the Jar:

First things first, make it as only you would. I imagined there being no cords coming out of the top of my tank. So I used a jar that had a hole pre-drilled near the base and supplied with hardware for re-sealing.

First I removed all the hardware from the jar and used a Dremel rotary tool to cut off the spout on the end so I had a conduit to pass the power cord and air line through.

This required me to cut the power cable for the powerhead and push it through the rubber grommet and my newly modified "conduit".

  1. Use a razor blade to remove any and all stickers from the glass jar.
  2. Using a dremel or saw or any kind, cut off the end of the spout.
  3. Using wire cutters, cut the power cable and after pushing it thru all the pieces, strip the wires and solder the leads back to their original form. Use tape or shrink wrap to cover up the exposed wiring.
  4. cut the clear tubing to longer than you think you need and push that thru next to the power cable.

Sealing the conduit to the tank glass:

Now we have everything we need inside the tank, and can seal the conduit.

  1. Place the rubber gromit into the hole.
  2. rub sealant around the threads and neck of the modified conduit. I used liquid nails, another option is waterproof caulking. Or Gorilla glue also would work.
  3. push the sealant covered modified conduit from outside toward inside.
  4. add some extra sealant around both inside and outside the conduit exit, we really don't want this to leak later on
  5. screw the nut down from inside and using a finger, wipe the excess sealant into a smooth edge all around both inside and outside of the conduit exit. Use a paper towel or rag to clean up the glass around that has any extra sealant on it still.

Plugging up extra space within the conduit:

the power cord and air line didn't completly fill up the conduit, so we need to use something to make it a fight fit of content inside the conduit so as to get a good watertight seal.

  1. Gorilla glue is good here as it expands to fill all the nooks and crannies of the conduit. Squeeze enough into the conduit to get a decent amount inside but not enough to start pouring into the inside of the tank and making a big sticky mess.
  2. I used kitchen skewers pre-dipped in water and then cut down to the length of the conduit and crammed as many as would fit into the now glued conduit. Gorilla glue does well with a bit of water.
  3. let it dry completely before adding water! I got a bit too anxious and tried curing the glue with a heat gun so as to water test same day as applying glue. This didn't work and I had to disassemble and clean. Then re-assemble with fresh glue to remedy my lack of patience.
  4. In an effort to make it look nicer, I wrapped the exit wounds with a scrap piece of leather I happened to have laying around my desk.

Mixing the saltwater:

Since you have to wait overnight anyway for the glue to dry, now is a good time to start mixing your salt mix. DO NOT USE SINK WATER! ordinary city water has toxic elements imbued into it for "sanitary purposes". It is not fit to sustain marine life.

1. Using RO/DI water (if you don't have a filter capable of removing all trace elements you can buy it by the gallon at most grocery stores) follow the directions on the salt package to make a solution that has 1.024 salinity. 1/2 cup salt for every gallon of water used.

2. Mix the salt and purified water in a container. Plug in the airpump and using another small length of the clear air tubing and the second airstone, get some bubbles going in your mix container. This will allow the water to circulate and properly mix the salt mix and water.

Step 5: Watching Glue Dry

While the glue dries there really isn't anything else to do. May as well sit back and browse the web for some idea's for what the best coral for your new tank will be! I personally have a small library of literature on coral care and husbandry, and decided to go with some light reading into this book.

I've decided I want some Zoa's and pom-pom xenia in this tank. But will likely end up adding a few frags of other things and see how they do as well.

Step 6: An Aquarists Best Friend

No matter how long you are in the aquarium keeping game, from the first moment you know your going to need a trusty sealed bucket...

I happened to have an old salt bucket at my house, really you just want a sealing lid (preferably o-ring seal, but the cheap orange buckets with lid from home depot do a good job as well) on your bucket of choice.

I like to have some salt water pre-mixed and aging for the times when I need to top off the tank from evaporation, and doing regular water change maintenance. really the trick to keeping water well mixed and "Aged", is to have some aeration in the bucket. this can be noisy to have bubbling water nearby 24/7, so I suggest doing as I have and drilling a hole big enough for an airline and some breathing room (i used a 7/16th drill bit).

This requires:

  • an extra airstone
  • enough extra airline tubing to run from the pump to the water aging facility (your 5gal bucket)
  • 5gal bucket with sealing lid
  • 2 inline air regulators and a "T" splitter for the airhose.

Process to setup aging tank off of the main tank airline:

  • Have an airpump with one outlet, so there is a 1ft length of tubing coming off of the pump, where it is split into 2 lines with a "T".
  • Then there are ~1ft lengths on each end of the "T" after which I put the air regulators (basic valve to control the amount of air passing through the airline) on each end.
  • Then it's just connecting one length to the airstone in the 5 gal bucket with lid. and the other to the line going into the display tank.

Step 7: A Seed of Biological Filtration

So you mixed the salt mix as directed on the box and aged it for 24hrs.

  • next day you came back and water tested the tank seals with ordinary tap water.
  • If it held water after a couple hours with a full tank, then drain it and dump the sand into the tank (i used a 5lb bag, it was a bit more sand than needed, but worked out well in the end)
  • Not pictured is me adding about 2 cups of "dirty" sand from one my my home reef's, this is a fast way to seed the necessary bacteria and micro-fauna to the tank for some good old biological filtration.

  • now fill the tank to a few inches from the rim with the "aged" saltwater.

  • turn on the airpump and powerhead, put the lights over the tank and let all that mix and settle in for a day or 2.
  • come back after letting that settle for a weekend and test your water paremeters. you will need to test PH and salinity. PH should be close to 8, and salinity needs to be very close to or at 1.024
    • use litmus paper or pre-made test strips to test basic water parameters.
    • use a hydrometer or refractometer to measure salinity.

if all looks well, then we can add the live rock next!

Step 8: Adding "live Rock"

No, I'm not talking about old fashioned rock and roll.

We want to add as much live rock as possible without making the tank look like just a small bottle of rocks submerged in water.

I ended up being able to fit ~7lbs of live rock in "Nantucket" here. Some of it even came with coral already on it! Good quality cultured live rock is not cheap by any means. I spent $40 on my live rock for this tiny little tank. But with the water cleansing lifeforms on these cultured rocks, it's worth every penny to spend the extra money on good rocks.

BE PICKY WHEN YOU ARE CHOOSING YOUR ROCKS! your going to see alot of them, so grab more than you need, and at the store try stacking them in an arangement that you think will fit in your tank. measure before this shopping trip, know how big the mouth of the tank is, and what the outer dimensions of the tank are. This is key information in finding just the right rocks for your new habitat.

adding the rock purchase to the running total of $180 gives us $220.

Step 9: Enjoy

this is not a complete reef setup by any means, but it IS a great start to a tiny tank. Really it takes weeks to completly setup a reef aquarium of any size. I was able to quickly get a baseline of life started in this tank because of the quality salt mix, my "dirty sand" from home, and a large amount of quality live rocks.

Price to play the game:

$220 for where the tank currently stands. I will be adding some coral frags, both from stock in my home tanks and some select pieces from the local fish store. After all is said and done, and the dust settles, I will have created a tiny desk aquarium for ~$300

Considering that I paid $350 for my biocube 14 glass tank some years ago, I believe I have successfully met my goal of building a reef on a budget.

To be continued!

  1. Create a light stand and complete the lighting. this entails making a arm for the lights and then adding some white LED and moonlights to complete the light spectrum I would like to have.
  2. Slowly add more coral frags (maybe 1 or 2 a week, trading out ones that are not adapting to the tiny tank life so readily)
  3. after the tank is fully established, and water quality maintenance has been figured out and maintained steady, one my contemplate adding ONE AND ONLY ONE FISH TYPE LIFEFORM. this tank is so small, and has so little in the way of filtration that more than one fish or similar lifeform will overburden the biological filtration and cause the tank to crash. Smaller tanks tend to crash harder, and faster than larger tanks. taking as little as a day or 2 to go from thriving and prosperous, to death and decay...
Age of Aquariums Contest

Participated in the
Age of Aquariums Contest

2 People Made This Project!


  • Sculpting Challenge

    Sculpting Challenge
  • 3D Printed Contest

    3D Printed Contest
  • Motor Vehicle Contest

    Motor Vehicle Contest

9 Discussions


5 years ago on Introduction

the tank has kept it's temperature constant with nothing more than ambient office heating/cooling. temp stays right around 76-78 F. a reasonable temperature.


5 years ago on Introduction

This looks excellent, both in presentation here and in real life at the Pier. It seems like this might be best for an experienced custodian of aquatic life rather than as an easier option than a larger tank.


Reply 5 years ago on Introduction

Indeed. I would suggest a fresh water tank to anyone any day and time. Marine tanks are quite difficult to maintain. And this one especially seeing as there is no filter or sump tank.

I personally have had fresh water tanks most of my life. And over the past few years have had marine tanks of large and small scale. Bigger is easier in marine aquariums, but if your looking for a bigger tank you gotta have space that can be permanently dedicated, and a huge budget.


5 years ago on Introduction

Hi! question, How hard is it to upkeep? Because I have never had saltwater, just freshwater and I have need really wanting to try this out. I would only have live rock and coral, no fish for now.

A tank tank this small would be highly unstable. If the nitrogen cycle gets out of balance even a little the entire thing could crash. I find nano tanks to simply be more work than they're worth. I like the idea, but unless you're keeping a freshwater tank with just some plants and shrimp, it becomes too much work. Also, how are you keeping the temperature stable?


5 years ago on Step 9

What is a good "water quality maintenance" system for this size tank? Coming from a fresh water tank - I have not done salt water. This sound like a really nice shrimp tank - How many shrimp with a small amount of rock do you think this would support? Still just one? Thanks.


Reply 5 years ago on Introduction

good question, i'm currently working on a instructable on water maintenance system for such a tiny tank.

My tactic thus far is to change out 1 mason jar of water every day, and to check the specific gravity of the water. i plan on bi-weekly changing out all of the water with new by using a hose to gravity feed the water out.

for shrimp you could get away with more than one, but i would not have more than 2 cleaner shrimp in a tank of this size, or more than 3 peppermint shrimp. trick here is keeping the livestock fed while still not disturbing the water quality.

cleaner shrimp:

peppermint shrimp:


Reply 5 years ago on Introduction

I love shrimps. I had red cherries and Amano shrimps in my 55 gallon fresh water.

I'd like to do an Instructable on
aquarium automation, where temperature, SG, and pH are monitored
continuously and trended on a internet connected system. But a decent
pH sensor is $100, and there doesn't seem to be any reasonably priced
continuous specific gravity sensors.