Reef Tank Test Kits – The Ones You Really Need!

If you are looking into test kits you must be well on your way to an amazing reef tank! Congratulations!

One of the first things you are GOING TO NEED when you set up your new aquarium is test kits. You will need these to monitor your water parameters during your tank cycle so you will know when it is ready for adding livestock. You will also need them to test weekly when you start adding corals.

Ammonia, nitrate, nitrite, pH, salinity & temperature test kits are needed to cycle a reef saltwater aquarium. Once corals begin to be added then calcium, magnesium, alkalinity, and phosphate test kits will be required to maintain perfect water parameters essential for a healthy saltwater aquarium.

I never had test kits when I was into freshwater as I never really needed to know what was going on with my tank. Just doing the regular weekly water changes kept everything in line. However, that all changed when I got into saltwater aquariums and the high cost of livestock came into play.




I personally love the Salifert range of test kits as they are PERFECT for knowing what is going on in your tank.

There is a test kit for every parameter you could ever need to monitor in your water, they are super simple to use and are explained very well in their instructions. These are the only kits I use!

Salifert test kits are recommended as the best test kit for saltwater aquariums by a vast majority of experienced reef keepers.

You can find the Salifert Range of Test Kits Here at

I have tried other kits and found that they were either not accurate enough, too expensive or were a hassle to use.

Which Test Kits Do You Need When First Starting A Saltwater Aquarium?

When you first fill your reef tank with water you are about to enter into the ‘Cycling Stage’ and you will need to monitor every day or two to see how your bacteria are building and how the biological filter is growing.

I recommended 5 things you will need to buy to monitor the progress of your tank when you first set it up and begin its cycle:

Digital Thermometer

To ensure your tank temperature remains constant at the set temperature. Most saltwater tanks are in the 78-80°F or 25-27° C range. The is the best time to get your temperature steady before adding livestock.


This simple tool is in every experienced reefer’s toolbox. It is used to monitor the salinity of the water daily, weekly to ensure the specific gravity of the water never fluctuates. You will need this when adding your salt to your batches of freshwater for your water changes.

Ammonia Test Kit

This is the first peak you will look for when cycling a tank. Ammonia is the source of food the bacteria will need to feed on and then multiply. You should start to see the Ammonia start to peak around the 7-10 day mark.

Nitrite Test Kit

This will be the next spike you are looking for. This is the bacteria turning the Ammonia into Nitrite. You can see on the chart, as Ammonia begins to decline the Nitrite is rising.

Nitrate Test Kit

The Nitrates are beginning to build and break down the harmful Nitrites into less harmful Nitrates. As you are testing every day or two you are waiting for the Ammonia and Nitrites to drop to zero, and then in a few weeks, the Nitrates should drop to zero as well.

For more information on the Nitrogen Cycle of an aquarium please read my article Here.

Which Test Kits Will You Need When You Begin To Add Corals To a Reef Tank?

Not all corals will need you to monitor any extra water parameters but once you start to get into corals that grow by creating a hard shell or skeleton, you will need to start monitoring a few extra water parameters.

Here are a few coral types you will need to start monitoring for element consumption:

  • LPS – eg: Frogspawns, Hammers & Torches
  • SPS – eg: Montipora, Acropora, Millipora & Chalice
  • Clams – eg: Derasa, Maxima, Squamosa

Soft Corals like Ricordia, Mushrooms, Zoanthids, Toadstools do not really require monitoring. They consume very little of the elements and regular water changes will keep these happy.

The corals bulleted above, especially SPS, consume Calcium, Magnesium, and Carbonate (Alkalinity) to build their skeletons. They can only get these elements from the water and once your corals start growing and you buy more, they can consume at a rapid rate.

Up to a certain point, your water changes will keep up with the demand but you will get to a point where you need to add these elements by dosing to your tank daily to ensure the prime levels are maintained to allow your corals to continue to grow.

You will need to monitor:

  • pH
  • Alkalinity
  • Calcium
  • Magnesium
  • Phosphate – If this is high it will prevent your corals from growing. Important to monitor with SPS Corals.

How Often Do You Need To Test Aquarium Water?

During your tank cycle, test every day or two until you see both Ammonia & Nitrite spike and then drop to zero and Nitrates rise then fall below 5ppm, preferably at zero. Nitrates in reef tanks are not good and you should always try to aim for zero or as close to it as you can.

When my reef was running without any hard corals I would just test for nitrates once a week before the water change.

Once I started adding LPS and SPS I would test once per week to monitor Nitrates, Calcium, Alkalinity, and Magnesium. If I found the alkalinity was being consumed rapidly I would test Alk and CAL every day for a week to monitor the drop each day. This would then show me an average of what each element is being consumed each day how much I needed to supplement between water changes.

Do You Test Aquarium Water At The Same Time?

Everything to do with your Coral Reef Aquarium is aiming for stability. Your testing regime is an important part of this stability program. Your main aim of water testing is about getting accurate results. When I test my reef, it is on Tuesday evening around 8pm each week. This provides me with a consistent benchmark.

Just like plants, your fish, coral, and bacteria all work on a daily cycle of activity. By testing at the same time of the day each week, you are testing in the same activity period as the last time. Your parameters can fluctuate throughout the day, so by testing at the same time you get the most accurate result.

How To Test Aquarium Water If You Are Color Blind?

Many people find matching colors on fluid-based aquarium test kit comparison cards very difficult, especially if their eyesight is not very good or they are color blind in the color range the test kit is using. Luckily there are some great test kits from Hanna that use a digital meter to give you a numeric reading you can read off the screen.

These are Awesome but are more expensive to purchase in the beginning. You can buy the refill kits to keep testing when your fluids run out thus preventing you have to buy the whole tester again. These are becoming very popular as there is no mistaking the reading given.

Hanna Digital Alkalinity Tester

Hanna Digital Calcium Tester

Hanna Digital Phosphate Tester

Click Here to see the Hanna Checkers at

Do Aquarium Water Test Kits Expire?

YES, Test Kits Do Expire – Salifert prints a ‘Use By’ date on the box to ensure the tests remain accurate. The chemical compounds used to test your water do deteriorate over time and Salifert wants to ensure your test results stay accurate.

Overdosing your reef can kill it! It has been done! Have a Google around the forums for people overdosing Alkalinity. It is more common than you would believe!

The test kits usually have a couple of years in which to be used, which is plenty. You will go through a lot of them once you get into SPS!

Aquarium Water Testing Tips:

  • Have a book or a whiteboard and write down all your test results each time you test. This will give you an easy way to track trends in any parameter. This has saved my butt more than once in identifying a problem early.
  • DO NOT Drink Beer or Wine While Testing! Seriously!
    I like to have a beer AFTER I have done my testing and maintenance. I used to have a beer or 3 while doing my Tuesday night maintenance until one night I almost crashed my tank by getting my alkalinity results wrong and started to adjust my dosing pump to suit.
    Luckily I caught the mistake the next day but it could have been fatal for my aquarium.
  • Test, Test & Test! All the tanks I have been to rescue have been mostly because of lack of testing. When I get a blank look off the owner as I ask what their Specific Gravity usually sits at or what’s the normal Alk level and I get the ‘Deer in the Headlights Look’ I know where to start.
  • Test at the same time, every week – Keep your results consistent.
  • Buy your test kit replacements before you run out. You never know when you may have an issue and need to test every day to prevent a tank crash. This saved my reef once!
  • Try not to be distracted when doing your testing – Distractions cause mistakes.
  • If a parameter looks off, test again. If it still looks off try a friends test kit in case you have a bad kit or a kit that has developed an issue.
  • If you mix batches of saltwater for big water changes, always test your batch before adding it to the tank, especially if you have just opened a new salt bucket.
    There have been times when a salt batch was wrong and testing was the only way to avoid a tank crash when adding your new water.
  • Ensure your new water going in matches the water coming out. Especially for Temperature and Salinity.
  • If you are heavy in SPS, match the Alkalinity, Calcium and Magnesium in the fresh batch too and give it time to mix before doing the water change.

To Finish

Salifert, in my opinion, makes the best test kits for saltwater aquariums with Hanna coming in closely behind with their digital checkers. However, their digital checkers are only available for a set range of parameters at this time.

The Salifert range is vast and you will find they have a test kit for almost any parameter you wish to test. Their instructions are super simple to follow, The results are easy to read and best of all they don’t take long to do.

Testing is an important part of monitoring your water to ensure your inhabitants are living in the best possible habitat that you can provide. Regular testing will alert you to declining trends which you can address early and prevent a disaster.

To help you even further I have created these FREE handy guides for you. If you would like them, and more please Click Here

To find all the products you will need during your cycle CLICK the image below to go to my recommended products guide:

Aquarium Cycle Essentials Header

Further Reading

You may find the following articles useful after reading this:

Great Products & Livestock at Great Prices!!!


Hi, I'm Richard and I have been an avid aquarist for over 30 years with a passion for Saltwater Aquariums. I love to pass on my knowledge to help others get the same amount a pleasure out of this hobby as I do. View my About Me page to find out more about me & my mixed reef aquarium.

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