This page contains affiliate links.  All that means for you is that if you click on one of my links and make a purchase, I receive a small commission.  This helps me keep this content 100% free!  But rest assured, I only recommend products I know and trust! Happy Reefing!

How To Setup A Saltwater Aquarium

There is a steep learning curve when setting up your first saltwater aquarium.  It took us several years of research before we got up the nerve to build our first tank.  But it doesn’t have to be that hard.

The 30-part video is meant for any person who wants to build their first saltwater fish tank.  It is meant to give you just enough information to get started without overloading you with too much.

As with any hobby, it takes thousands of hours to be an expert, but only a few to get the basics.

If you follow the steps below, you could have a saltwater fish tank up and running next week.  Happy Reefing!

Step 01: Choose Your Budget

To make it a bit easier, we have compiled several build lists at different price points.  Click HERE to browse all of the build lists.  You won’t go wrong with whatever you choose, but do look at them carefully to see which one suits your needs and desires best!

If you are set on a larger tank but don’t have the money today, then just do what most of us in the hobby do… buy a piece of equipment with each paycheck.  Regardless of which price-point you choose, the end result is going to be beautiful.  

Step 02: Purchase Items

The nice thing about My First Fish Tank, is we make all of our money from affiliate commissions, which allows us to use several different online retailers.  We only recommend products we like, since what would be the point of recommending a crappy tank!

We use a few different online retailers in order to get our preferred products at competitive prices.  So just open up a few tabs in your browser, add everything to your carts, and you’ll have a few exciting shipments heading your way!

Step 03: Choose Location

You’ve ordered your essential items so let’s figure out where your tank is going to reside.  Choosing your location is not rocket science, but there are a few do’s and don’ts you want to keep in mind.

Do choose a location with electrical outlets nearby, and make sure that circuit can handle the load.  You could do an easy test by plugging in some high amperage items such as a vacuum, space heater, or hair dryer and turning them on at the same time.  As long as your circuit doesn’t break, you should be alright. 

Don’t put the tank in direct sunlight.  A little bit will be okay, but too much direct sunlight can cause unwanted algae growth and temperature swings.

Do choose a location that has easy access for maintenance.  You are going to be spending a lot of time keeping things pretty, so the closer to a utility closet or garage the better.

Don’t put the tank over a vent or next to a floorboard heater or wood burning stove.  Daily temperature swings of even a few degrees can cause stress for your livestock.

Do make certain your table/stand/counter, or floor can withstand the weight of your aquarium.  1 gallon of water weighs 8.3 lbs, so a 20 gallon tank is going to weigh over 160 lbs in water alone. And for everybody else in the world who is not from the United States, 1 liter of water weighs 1 kg. 

Don’t put the tank in your bedroom, unless a constant low-level gurgling and buzzing noise is your thing!  I have several tanks in my bedroom, so we have to sleep with a fan on to drown out the noise.

Step 04: Unpack Aquarium

When your aquarium arrives, give it a quick visual inspection to make sure there are no obvious cracks or defects.  It is glass, so sometimes it can be damaged during shipping. Glass aquariums are heavy, so it’s always a good idea to have a helper so this doesn’t happen. (shattering glass).

Step 05: Assemble Stand (Optional)

Most build lists don’t have a stand, so you can just skip this step.  If you did purchase a stand, just follow the included instructions to get it assembled.  If you plan on using your own stand, make sure it is strong enough to support the weight of the tank.

Step 06: Cut Foam Mat (Optional)

All of the build lists at My First Fish Tank either come with pre-cut mats or they don’t require them.  But if you are building your own system, be sure to carefully cut the neoprene foam/yoga mat to fit perfectly underneath your tank.  Small irregularities in the top of the stand could lead to stress fractures and ultimately tank failure over time. So do yourself and your home a favor and use foam!

Step 07: Place Aquarium On Stand (Or Table, Or Counter)

Wipe off the top of the stand/table/counter, and the bottom of the tank.  With your helper, team lift the tank into place, being sure it is perfectly centered on the foam pad.  Leave about a fist size space between the tank and the wall to allow access for cleaning and equipment.  Do a preliminary leveling using shims if necessary, before moving onto the next step.

If you purchased a larger system with a sump, you will also need to follow the instructions provided, and install the prefabricated plumbing.  This will allow you to move onto the next step and leak test both the tank and sump.

Step 08: Fill With Tap Water And Leak Test

Tanks can be damaged during shipping, and a small leak can lead to a big headache.  Fill your tank with tap water. You can use a bucket, pitcher, or hose. It doesn’t matter at this point, because you are just going to drain it in a couple hours.  Once full, give the outside of a tank a quick wipe to make sure it is completely dry. Now closely inspect your tank, especially around the seams, to ensure there are no leaks.

Step 09: Level Your Tank

With the tank full of water, we’re now going to level the aquarium.  A couple quick notes here. If you purchased a 20 gallon system or less, you will most likely skip this step.  Never place composite shims directly under the tank. Only use shims to level the aquarium stand.

Laying the level on top of the tank, check all angles to get a sense of where to place the composite shims.  Place the shim underneath the stand, with the ribbed side facing down. Use a hammer to gently tap it into place.  You will likely need to use several shims at different locations on the stand. Once the tank is level, break the shim by pulling up.

Step 10: Drain The Tank

There are two ways to start a siphon.  Option one: the mouth method. Make sure your gravel vacuum is clean.  Stick the large end of the vacuum under the water line. Bring the small end of the tube to your mouth, being sure it is above the water line.  Suck in the water until it nearly reaches your mouth and place your thumb over the end. Then lower the small end of the tube into the bucket, release your thumb, and your siphon is started.  

Option two: the mouth free method.  Hold your thumb over the small end of the tube.  Fill the large end of the vacuum with water. Place the small end over the bucket, release your thumb, and once water starts flowing into the bucket, quickly place your thumb back over the tube.  Then stick the large end of the vacuum into the tank, being sure to keep it facing up. Fill the vacuum with water, then keeping it below the water line, flip the vacuum downward. Remove your thumb and your siphon is started. 

Step 11: Make Or Buy Saltwater

You have three options here.  Option one is to purchase pre-made saltwater from your local fish store.  Just get a bunch of 5 gallon buckets and make the trek.

Option two is to purchase RO/DI water from your local fish store, and then mix the salt yourself.

Option three requires you to purchase an RO/DI filter and make the saltwater yourself.

Here’s how to make saltwater.  Make sure to only use RO/DI water, never tap water or distilled water.  Read the directions on your salt mix container to estimate how much you will need.  Slowly add in salt while stirring. Measure the salinity with your hydrometer or refractometer, and add salt mix or RO/DI water to bring the salinity to 33-35 ppm.

Once you have livestock in your tank, you will also need to add the additional step of heating your saltwater mix to match the temperature of your display tank before doing any water changes.

Step 12: Add Rock & Aquascape

You can use your own aesthetic judgement here.  But here are a couple things to consider. Make sure that your aquascape is stable, and that a grazing snail or strong water current won’t topple it.  Leave enough space between the aquascape and the glass to allow for easy cleaning. And lastly, be sure to provide hiding places for shy fish and invertebrates.

Step 13: Add Sand (Optional)

If you didn’t purchase the optional sand and/or just prefer a bare bottom tank, skip this step.  Do not rinse the live-sand. Instead, just pour the bag out directly into your tank, and spread it evenly around your aquascape.  Sand is not an essential element for a saltwater aquarium, although some species of fish and invertebrates will require a sandbed for burrowing, protection, and food.

Step 14: Add Return Pump

It is easier to add the return pump before adding saltwater.  While not absolutely essential, I recommend using the optional plastic hose clamps to secure the flexible tubing to the pump.  Stay clear of the traditional metal hose clamps, as they will rust over time.

Step 15: Add Saltwater

To avoid splatter, pour saltwater directly onto your stable aquascape, or place a small plate directly on top of the sand bed, and pour the water into it.  Regardless of what you do, expect a cloudy tank if you used live-sand. There is usually a packet of water clarifer that comes with the live-sand. Add that to the tank now to speed in the clearing up of the tank.

Step 16: Organize Wires & Install Drip Loops

Water and electricity do not play well together.  For your safety, be sure that your outlet is protected from accidental water splashing.  It is also best practice to make sure your outlet is protected by a gfci.

I highly recommend using the optional surge protector, as it has five individually controlled outlets which will make tank maintenance a breeze.  Use either a label maker or tape to label each cord.

Be sure to install drip loops wherever necessary.  A drip loop is just a loop in your electrical wire that goes down below the outlet and then back up to the outlet.  This will protect your outlet from water that may run down the wires by accident. A cheap zip tie or cord clip is an affordable solution when installing drip loops.

Step 17: Add Mechanical Filtration

Place your sponge and/or polyester filter floss into the the rear filtration chamber or sump.

Step 18: Add The Primary Heater

We like to put our heaters in the rear filtration chamber or sump.  Just make sure that wherever you put it has decent flow to transport the warm water throughout the tank.  

A quick note about heaters. They need to be calibrated. Set your heater to 78 degrees fahrenheit (or 25 degrees centigrade).  Place it into your aquarium, making sure it is covered with water. Give it a day and use your thermometer to check the temperature.  Your heater will likely be off by 1-3 degrees. Remove your heater, and adjust the calibration dial to match the water temperature. Then adjust the temperature to reflect the new 78 degrees.

Step 19: Add Backup Heater (Optional)

If you bought the optional backup heater, install that now.  Even the best heater will eventually fail, and a backup heater is the best redundancy protection for your tank.  Here’s how the backup heater works. Follow the instructions from step 18 to calibrate it. Then, lower the temperature of the backup heater to 76 degrees fahrenheit or 24 degrees centigrade.  

Then at some point in the future, when you notice the temperature of the tank is only 76 degrees, you will know that the primary heater has given out and it’s time to order another heater. You can then promote your backup to primary and be thankful your livestock are still alive and happy!

Step 20: Turn On The Return Pump

Turn on your return pump to start filtering your tank.  It will take a while for the sand to settle, so just be patient as the cloudiness clears.

Step 21: Install & Turn On Wavemaker/Powerhead

If you did not purchase a wavemaker, just skip this step. Attach the wavemaker to the side of the tank.  Make sure it is a few inches below the water line to avoid any air sucking noises that may occur. Turn on the wavemaker and set it to medium for now.  You will be able to make adjustments to it later.

Step 22: Install Lights

Most lights are not waterproof, so make sure to install these carefully.  If you have lights as a part of your canopy, then just put the canopy into place.  There are various mounting options here, so follow the instructions with your lights to securely mount them to the sides or rear of the tank.  We like to hide the wire behind the tank. Plug them in and turn them on.

Step 23: Cycle The Tank

Cycling your tank is hobbyist lingo for establishing a bacteria colony in your live rock to remove the toxins (specifically ammonia), that are caused by livestock waste and uneaten food.  

There are two ways to cycle the tank.  The first method is fishless. Add a piece of frozen shrimp or add a couple tablespoons of fish food.  Do not change your filter during this time and if you have a protein skimmer, make sure it is off. Test your water for ammonia, nitrite, and nitrate every few days, and record the results in a log.  You will see your ammonia spike first, followed by nitrite, and finally nitrate. Once your ammonia and nitrite levels have returned to near zero, the cycle is complete.

The second method is the fish method.  I recommend using Dr. Tim’s Ammonium Chloride combined with Dr. Tim’s One and Only to speed up the cycle.  Then add a couple of hardy fish such as clownfish or damsel fish. Keep the protein skimmer off and only clean the mechanical filter once a week.  Test for ammonia, nitrite, and nitrate every few days and record the results in a log. If ammonia levels reach 1 ppm, you will need to perform a 15%-30% water change to reduce the ammonia levels.  Once the ammonia and nitrite levels return to near zero, your tank is cycled.  

A full cycle takes 4-6 weeks.

Step 24: Perform a 25% Water Change

Once the cycle is complete, a 25% water change will help remove any remaining nitrates.  If you have a protein skimmer, you can now turn it on. If you already have fish in the aquarium, be sure to heat your new saltwater to within a degree or two of the aquarium water to avoid stressing out your fish.  Turn off your return pump and wavemaker before starting the siphon. Use a pitcher or bucket to easily add the new saltwater to the aquarium.

Step 25: Buy Fish

Start by purchasing 2 hardy fish from your local fish store, such as clownfish or damsel fish.  Even though your tank is now cycled, the addition of fish can cause a second mini-spike of ammonia, so be sure to to test for ammonia every week.

Step 26: Drip Acclimate Fish

Drip acclimating your fish is the process of slowly equalizing the water parameters from the fish store to your aquarium.  It is crucial as temperature, pH, and salinity will likely be different in your aquarium.

The most important thing to remember here is you never want to add water from your local fish store into your aquarium.

First, rinse off the outside of the bag with fresh water.  Turn off your aquarium lights, and float the bag in your aquarium for 15 minutes to help equalize the temperatures.

Take a long portion of airline tubing and tie a couple of loose knots in it.  Using a clean bucket or receptacle that you only use for fish, cut the top off of the bag, and gently pour the fish and water into the bucket.  

Place one end of the airline tubing in your aquarium, and the other in your bucket, being sure to start a siphon first.  Adjust the tightness of the knots so you get between 1-2 drops per second.

Drip acclimate the fish for 30 minutes.  If the room you are in is chilly, you may want to consider adding a small heater into the container so the water temperature stays near 78 degrees.After 30 minutes, remove the airline tubing and rinse it with fresh water.

Step 27: Add Fish To Tank

Setting up a quarantine tank is considered the gold standard of marine husbandry and is best practice for keeping your livestock disease free.  Check out our video on how to set up a quarantine tank.

Keeping the aquarium lights off while introducing fish to your aquarium will help reduce their stress levels.  Using a net or small bowl, catch the fish, being gentle and patient as they can be injured easily. If you are using a net, just give it a couple quick bounces to get rid of any local fish store water.  Then gently pinch the end of the net around fish, turn the net upside down , and release your fish. If you are using a bowl, just hold you hand over the top and drain the water out before adding your fish.

Many fish jump, and there is nothing worse than coming home and finding one of your pets dead on the carpet.  I always recommend purchasing or making a mesh screen kit. Check out this video on how to make your own clear mesh screen.

Step 28: Turn On Lights

Give your fish a few hours to explore their new home before turning the lights on.  If you have programmable lights, turn them on slowly over the course of the day. If you just have an on/off switch for your lights, consider letting the fish get used to their tank for one entire night before turning the lights on.

Step 29: Rinse All Equipment In Freshwater

Saltwater is quite corrosive to your equipment, so anytime something comes in contact with saltwater, be sure to give it a thorough freshwater clean in the sink.  Make sure to get the inside of any piping or tubes, and never use soap as soapy residue can be detrimental to your livestock. A small amount of tap water won’t hurt your tank, but if you can let your equipment dry completely first, that would be best.

Step 30: Send Us Pictures And Follow Us!


Marine Depot Aquarium Supplies