Complete Saltwater Aquarium Kit – How To Start A Saltwater Fish Tank

Complete Saltwater Aquarium Kit – How To Start A Saltwater Fish Tank


In this article you will be learning how to start a saltwater fish tank and I will provide a list with all the required components for a complete saltwater aquarium kit. This process will get you started easily. A saltwater fish tank can be much more work than a freshwater aquarium. This system design is for easy maintenance with a minimal amount of work.

Fish Only with Live Rock (FOWLR)

This article assumes you’re not going to dive into growing corals which is much trickier than only fish and some live rock. Once you feel comfortable maintaining your FOWLR tank you can consider adding corals. For now we’ll keep it simple.

How To Start A Saltwater Fish Tank

A complete saltwater aquarium kit should include thorough instructions on how to start a saltwater fish tank. We’ll start out first with what’s going to go into your tank and be involved with caring for it first. Afterward we’ll cover the components you’ll need for your complete saltwater aquarium kit.

Fish Selection

It’s important not to select your fish based solely on what you would like to keep in your aquarium. Many fish are not compatible with other fish. You need to carefully select the fish you intend to keep. has a great Compatibility Chart you should reference when making your decisions. It includes almost everything you could want and also includes compatibility with live corals so you’ll know if you can add corals to your tank later without having to find a new home for some of your fish. LiveAquaria also does a very good job of outlining the dificuly with keeping particular fish and their nutritional requirements. I’ve put together a good article on reef safe fish if you know you eventually want to add corals to your tank.

Fish Acclimation

Saltwater fish are generally more delicate than freshwater fish. The also tend to be a lot more expensive than freshwater fish. To give your new little buddies the best opportunity to thrive you should wait to introduce them to your tank until it has been set up a week or so. This will give things a little time to stabilize. When you get your fish and are ready to put them in your tank, you will want to slowly acclimate them to the water.

Fish Acclimation Steps

  • Place the bag with the fish in the tank for 10 minutes so the temperature of the water in the bag will match that of the tank.
  • Next, add a cup or less of tank water to the bag and wait 10 minutes.
  • Repeat this process 3 or 4 more times.
  • Once you feel a large amount of tank water has been added to the bag you can gently release you new little buddy into the tank.


After you select your fish you need to keep in mind what they’ll need to eat. Some are carnivores. Some are herbivores. And some are omnivores. Make sure you prepare to feed them the proper food and do your best not to overfeed. Overfeeding leads to many problems with nitrate and phosphate control.

Live Rock

Live rock is the primary filter in a saltwater aquarium and not just decoration. You’ll want to pay special attention to this part of the process. How much live rock do you need? Most typically suggest 1 to 2 pounds per gallon but that’s a very vague estimate. In general you can’t have too much rock but you’ll want to factor in how you’d like to aquascape your tank. Take a minute to skim this short article on live rock before you pull the trigger. It’ll give you a good handle on what to expect with live rock.

Live Sand

Sand is generally an aesthetic choice these days though it wasn’t long ago that it was a factor similar to live rock. Some people even opt not to have any sand in the bottom of their tank now. I prefer a little sand in my tank bottom for aesthetic reasons. The best suggestion I can have is to either go with no sand or only an inch or less. Sand can collect fish waste and uneaten food which means you will need to clean it from time to time. If there’s no sand there’s no sand to clean. If there’s only a small amount there’s only a small amount to clean. Yes, I have an article all about live sand worth skimming through too.


Macroalgae is a very successful method of removing phosphates from your aquarium and essential to a complete saltwater aquarium kit. Removing phosphates prevents nuisance algae outbreaks. Macroalgae is great because it’s easy to manage and hide in your sump. The area of your sump you place the macroalgae in is called a refugiumChaetomorpha is the macroalgae to get. It is very fast growing and stays in a tight bunch so it’s easy to manage and not likely to accidentally get into your main tank and cause problems. Even if it does get in there it’s easy to remove unlike some others. You’ll need a grow light and a timer to turn it on and off automatically. The best cycle is to turn it on when you turn off the main light in your display. Then turn off the refugium light when your main tank light turns back on. Once a month you’ll simply remove a third of your chaetomorpha and throw it away.


One big difference between a freshwater tank and a saltwater tank is you can’t use tap water and just add some chemicals to make it safe. You’ll either need to go by your local fish store (LFS) and purchase water from them or you’ll need to get a RO/DI filter to purify your water. I highly recommend getting a RO/DI filter since lugging heavy jugs from the store regularly for water changes will get old very fast. If you’re looking to get set up quick there’s nothing wrong with skipping it for now and purchasing saltwater from your local fish store.

Using a RO/DI filter

A complete saltwater aquarium kit should take into account water changes. An RO/DI filter will make you self sufficient in this area. Some people rely on a local fish store to purchase their water but this can get old fast. If, or more likely, when you purchase a RO/DI filter you’ll need to purchase a good quality aquarium salt and obviously you’ll need a large container for collecting the water you filter. It would be smart to get a heater and a cheap powerhead you can drop into the container so that when you add the salt the powerhead can mix it in and a heater will get the water up to the same temp as your aquarium water so you won’t shock your fish.


  • Topping Off with RO/DI Water – Daily
    Evaporation is a daily problem that needs to be dealt with. You can simply pour a little RO/DI freshwater (no salt added) to top off your aquarium and check to ensure the salinity is correct. Like I say above, this can get a little tedious I suggest a good auto top off (ATO) kit to handle this for you. A good ATO will turn this from a daily nuisance to an easy monthly task.
  • Regular Water Changes – Monthly
    The most reliable way to keep your saltwater tank healthy and happy is regular water changes. 10-20% water change once per month is optimal. Be sure the saltwater you put back into your aquarium uses a quality sea salt. The reason for this is that trace elements such as magnesium, potassium, calcium, etc. help maintain the health of your tank inhabitants and a good sea salt will contain these elements.
  • Regular Pruning of Refugium Macroalgae – Monthly
    Macroalgae in your refugium is the primary method for removing phosphates. Phosphates are what algae feed on and keeping phosphates in your tank low will reduce nuisance algae outbreaks. When you do your monthly water change toss out a third of your macroalgae.
  • Changing Media – Monthly to Every Few Months
    If you’re using a media reactor the you will need to change the media from time to time. This will vary based on the media you are using. I’m only suggesting using carbon to start, if you want to use a reactor at all. Using a reactor will typically be supplemental and meant to address a specific issues. Carbon will primarily help with yellowing of your water and remove microscopic junk. Other example uses for a reactor are GFO for controlling phosphate or Biopellets for controlling nitrate and phosphate.
  • Cleaning Your Pumps – Between Every 6 Months to Yearly
    You will need to clean your pumps from time to time. It’s not uncommon for powerheads to have coralline algae buildup that you can remov by soaking them in vinegar. Return pumps should also be disassembled and thoroughly cleaned.


You should test the following each time you change your water:

  • Salinity

    Should be maintained between 1.024-1.025

    • Test with:
    • What causes your Salinity to rise?
      Evaporation causes salinity to rise because the water evaporates out but it doesn’t take the salt with it. The same amount of salt is in the tank with less water.
    • What should you do if your Salinity is too high?
      • Short Term: Add RO/DI water purchased from your local fish store or from your RO/DI filter.
      • Long Term: You will need to top off your tank regularly with RO/DI water. You can do this by simply pouring it in or use an auto top off.
  • Nitrate

    Should be maintained near zero

    • Test with:
    • What causes your Nitrates to rise?
      Short answer is the breaking down of fish waste and uneaten food. Overfeeding is the primary cause but there could be an issue with your protein skimmer as well.
    • What should you do if your Nitrates are too high?
      • Short Term: Do a water change of at least 20%. Test again and repeat if necessary.
      • Long Term: Reduce the amount you’re feeding. Check your protein skimmer.
      • Additional Options: If adjusting your feeding amount and your protein skimmer appears to be working well you can add a reactor with biopellets. Biopellets will neutralize nitrates.
  • Phosphate

    Should be maintained near zero

    • Test with:
    • What causes your Phosphates to rise?
      Short answer is the breaking down of fish waste and uneaten food. Overfeeding is the primary cause but there could be an issue with your protein skimmer or refugium as well.
    • What should you do if your Phosphates are too high?
      • Short Term: Do a water change of at least 20%. Test again and repeat if necessary.
      • Long Term: Reduce the amount you’re feeding. Check your protein skimmer. Check your refugium light and macroalgae.
      • Additional Options: If adjusting your feeding amount and your protein skimmer and refugium appear to be working well you can add a reactor with GFO. GFO will absorb Phosphates.
  • Temperature

    Should be between 78-80 degrees

    • Test with:
    • What should you do if your Temperature is out of range?
      If you find your temperature is too high or low and you haven’t had issues previously you may have an issue with your heater. Heaters are prone to failure and some recommend changing them yearly. When your water temperature is too high, do not put ice in your aquarium. Tap water has lots of phosphates and will almost certainly cause an algae outbreak. If you’re concerned about how high the temperature is, unplug your heater immediately and if you really feel you need to drop the temperature put some ice in a plastic bag and place it in your sump. Keep an eye on the temp and get a replacement heater immediately. Given how cheap they are it’s good to keep a spare heater on hand if a local fish store isn’t nearby.

Complete Saltwater Aquarium Kit

If you’ve read along this far and feel that you’re up for the challenge of maintaining a saltwater aquarium, congrats! Now let’s list out the items you’ll need for your beginner saltwater aquarium.


SC Aquariums 50 Gallon PNP

This particular aquarium recently came out on top in a beginner saltwater aquarium review. It’s a great choice because it comes with a sump, stand, return pump and protein skimmer. The sump is sizable and beneath the display tank within the stand. If you’re not familiar with what a sump is you can think of it as a smaller aquarium beneath your main aquarium. The purpose is to hide additional equipment like a protein skimmer, add to the total water volume which stabilizes water parameter fluctuations, and houses a refugium containing macroalgae which removes phosphates.


EHEIM Jager Aquarium Thermostat Heater

The EHEIM Jager is known as the most reliable heater around. Heaters are prone to failure so going for the best is wise. I suggest plugging it into the Inkbird 308S. Use the Inkbird to turn it on at off at a predetermined temperature and set the temp on the Jager to just above the Inkbird. The digital probe of the Inkbird will be more accurate and reliable and the Jager thermostat will act as a backup.


Hydor Koralia Evolution

Water flow is important to getting water into the live rock where bacteria can breakdown fish waste and uneaten food. The SC Aquariums 50 Gallon PNP includes a return pump which will create some flow but adding a powerhead into the aquarium will add some flow and allow you to direct the flow better toward areas that may not be getting much. You want to avoid dead spots of flow or places where detritus can build up. There are many great options for powerheads available but the Hydor Koralia is inexpensive and very good.


AquaIllumination Prime HD

AquaIllumination ranked as the #1 brand in our LED aquarium light review. It edged out Ecotech based on its value. The AI Prime HD is the entry level fixture from AI and it is more than adequate for a FOWLR tank. Plus it’s feature-packed! Also, if you plan to add corals later it’ll be up to the task. If you find that you need more light to support corals you can easily add another Prime HD to the mix.

Refugium Light:

Kessil H80 Tuna Flora

The key to keeping algae out of your main tank is to provide a better environment for it to grow. The Kessil H80 is specifically designed as a grow light. It’s an ideal light for growing macroalgae like chateomorpha.


SODIAL Glass Seawater Thermometer

Thermometers are inexpensive but important pieces of equipment. The SODIAL Thermometer is great for placing in your sump. And it has the bonus of also being able to measure salinity.

Heater Controller (Optional):

Inkbird Pre-Wired 308S Digital Thermometer

The Inkbird Digital Thermometer controls 2 outlets based on the temperature and as mentioned previously, will act as the primary method for switching on your heater. It’s not required but it’s inexpensive and a good additional bit of security.

Carbon Reactor (Optional):

Reef Octopus Beginner OCT-MF300B 2.5 Inch Media Reactor

While not required, adding a carbon reactor to your aquarium will help maintain water quality and clarity.

Auto Top Off (Optional):

Tunze Osmolator 3155

A good auto top off will relieve you of a lot of daily maintenance. You also want it to be reliable and have redundancy so that you will be far less likely to have water overflow onto your floor. The Tunze Osmolator 3155 is highly recommended and well regarded.

Aquarium Controller (Optional):

Neptune Apex

This isn’t a cheap option but it’s a powerful one. An aquarium controller includes a salinity probe and a temperature probe for monitoring those parameters and can email or text you if something gets out of whack. Also you can plug in devices to the supplied power bar and you can turn devices on and off based on temperature, salinity, or schedule. You can also monitor the power being used by a device like a pump. If the power usage goes up it is an indication of blockage or buildup. This let’s you know when a pump or media reactor needs to be cleaned. There are loads of additions that are available to monitor and control all kinds of devices and automate some regular maintenance.

Supplies: Chaetomorpha, Carbon, & Cleaning Tools

Chaetomorpha is required for your sump and carbon is required if you opted to go with the Carbon Reactor. Primary cleaning tools should be a good magnet glass cleaner and a siphon for water changes.

Putting It All Together

First things first, take it slow. Once you get your equipment take your time setting it up. Don’t rush to get fish into your tank. Next, get your sand, live rock, and water into your aquarium along with macroalgae in the aquarium and allow it to run for a week or so while putting a small amount of food in daily. When the tank is good and broke in begin adding fish consider adding only a couple first and try to choose the most hardy of the fish you intend to keep.

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