Best Calcium Test Kit: Are They Accurate?

Honestly, things tend to be quite confusing when you observe that your corals and invertebrates have problems with their growth.

On top of that, they suffer from health-related issues as well. What could’ve gone wrong? 

Well, let me tell you what went wrong! Perhaps the calcium level in your aquarium just isn’t within range. Maybe it’s too high or low. And that could cause your corals and other animals to suffer. 

The only way to find this is to use the best calcium test kit in your reef tank. By using this kit, you can easily find out the calcium levels and act accordingly. 

Hence, we’ve researched for a while so that you don’t have to go through the hassle. And finally, we’ve handpicked the 5 best out of them. 

As if that wasn’t enough, we’ve even included the buying guide section and some informative points for you. So, let the hunt for the best test kit begin- 

Comparison Table

Product Overview

When it comes to the best test kit for measuring calcium, nothing beats the HI758 testing kit from Hanna Instruments. Well, this isn’t our favorite product for no reason. 

The unique feature of this product is that it’s the only electronic testing device on our list. So, it better be good. Let’s begin with the features- 

To start, yes, it’s the only electronic device on our list. So, it makes testing quite effortless. To be precise, this product finishes the entire testing of calcium in 3 steps only. 

So, when it comes to testing calcium, you won’t have to wait long. And, neither would you have to put in much effort behind the testing. 

For some people, time matters a lot! And that makes this product admired by many. Now, the testing kit doesn’t cause many errors at all, if any.

Here, you won’t even have to deal with color-changing complications. 

All you have to do is just look at the large and bright LCD screen for the results.

On the screen, the calcium level will be displayed in larger fonts. As a result, you’ll know straight away what you’re dealing with. 

So you won’t face any color-changing complications whatsoever. And, to make things even better, you won’t have to worry about problems with titration. 

Thus, the product makes everything feel quite effortless. All you have to do is just wait for the instant result, and it’ll show it on the large screen. 

Since it’s an electronic device, you might be thinking about the battery situation. Well, it runs on a single AAA battery. And the battery life is pretty damn impressive. 

Plus, the manufacturers have taken steps to increase the battery life. But how?

Well, the screen shuts off itself after some time displaying the results. So, you can forget about the screen time as it’ll stop. 

Moving on, the testing kit does provide instant results. But are they accurate? Yes, the results are pretty accurate and consistent. Even though you don’t have to do titration on it, the results will be around  +/- 6%. 

So, the product is reliable and consistent. If you’ve loved our favorite product on this list, then buy it.

Even though it’s expensive, it’ll save you a bit of hassle and time. 


  • The results are instant and consistent
  • Easy to work with
  • Doesn’t provide color-changing complications
  • The screen shuts off to save battery
  • Provides accurate results faster


  • Expensive
  • Plastic latches could be more durable

Product Overview

Bringing in the runners-up of this list- Red Sea Reef Foundation Calcium Test Kit. The best part about this testing kit is its easy usage and accurate results. 

Well, yes, the standout factor is that this testing kit comes with an accuracy of +/- 2%!. On top of that, it provides consistent results almost all the time. 

So, let’s begin with the other features of this product- 

Starting, the testing kit includes a storage case and glass vials in the box. So, you won’t have to go in the extra yard and buy them. Plus, the instructions come laminated, and they’re easy to read as well. 

Add to that; the testing kit includes 75 calcium testing kits. So, you have your options.

Other than that, the uniquely shaped titration tool is one-handed. 

Moreover, it even prevents the spilling of water. Another impressive thing about this titration tool is the release of consistent drops. So it’s easier to pick up the results when testing. 

Even if that’s not enough for you, the change of color is distinct all the time. As a result, it’ll help the users determine the results.

It’ll make the endpoint even clearer. So, your experiment results will be out, and you’ll know the calcium level. 

So, yes, the product makes testing easier and effortless. On top of that, the product comes with syringe holders as well. This makes the experiment feel easy. 

All in all, this product makes experimenting easier due to the provided tools in the box. Plus, with accurate and consistent readings, you won’t have to worry much about the testing. 

So, in the end, this reliable testing kit is all you need. And, if the features and benefits have grabbed your attention, we’d advise you to purchase. 

Because you won’t be disappointed by any means, the easy experimenting process makes everything easier all the time. 


  • The process of testing is easier
  • The color change is easier to read
  • Comes with instructions
  • Prevents spilling of water
  • Provides accurate and consistent results


  • Leaks at times

Product Overview

They say, “third time’s the charm”. So, let’s see if you love our third product. Here, we have the Calcium test kit from the brand- Salifert. The best part about this product is that it provides up to 100 tests maximum. 

On top of that, it provides maximum accuracy almost all the time. So, let’s begin with the features of this product- 

First off, the kits are designed to provide precise and accurate readings. Here, the testing kit shows a contrasting change of colors every time. 

As a result, you can judge whether the calcium level of the aquarium is within the range.

Another benefit of the contrasting colors is that the testing kits are easier to read as well. So you’ll never have to guess your decisions second. 

The testing kits ensure that they’ll detect even the smallest traces of calcium.

The impressive part is that it won’t interfere with other chemicals anytime. 

So, the calcium testing kits work at resolving all the calcium contents only.

There’s no chance of interference whatsoever. This is why you can track your calcium levels and ensure the health of your corals. 

In the end, you’ll get all the help from this testing kit as it’ll provide all the instructions. And, yes, it’s easier to use this product as well. 

Additionally, the easier reading of the tests makes it even better to use this product. Plus, it doesn’t cost that much.

So, if the features impress you, go ahead with the purchase. We’re sure you won’t be disappointed. 


  • Provides accurate and precise reading
  • Doesn’t interfere with other chemicals
  • Provides a lot of testing kits
  • Affordable option
  • Contrasting colors make it easier to read the results


  • Testing time can be a bit high

Product Overview

Presenting the most affordable product on our list- API calcium testing kit. Because the product comes at a lower price, many people could question its accuracy. 

Fear not! API products have been known for their affordable prices all the time. They all have lived up to the brand’s reputation for being excellent-quality products. 

So, let’s talk a bit about this particular product- 

One thing everyone underestimates about testing kits is the experiment process. While we do believe this product is easy to use, it has some drawbacks. But let’s begin with the process; first off- 

The vial should be filled up with the water from the aquarium. Then, proceed with the solution bottle, as you’ll shake it up.

Next, drop it into the vial and observe the colors changing to blue. 

Even though it works well in the case of this product, you’ll have to put in an additional step. Here, you’ll need to shake the vial every time after dropping in each drop. As a result, it’ll eat up some time. 

As if that’s not enough, some drops leak out of the vial. Even though there’s a plastic cap, it’s still not enough to stop the small drops. That can be an absolute pain! 

Moving on, this product comes with an accuracy of 20 mg/L. Well, this isn’t bad, to begin with. But, it does lack behind the previous product. 

Regarding reliability and precision, this kit held up pretty well too. We’ve tested this kit ourselves for quite some time against other competition too. And, all of the time, the kit provided consistent results. 

So, it’s safe to say that this kit is reliable even though it comes at a lower price. That’s why if you’re looking to save up some cash, give this product a look. 

With a lower price and great features, this product brings a lot to the table. It offers a great deal. 


  • Comes at a lower price
  • Easy to read
  • Pretty straightforward usage
  • It’s reliable and precise


  • You’ll need to shake the vial every time when experimenting
  • Leaks a bit from the testing vials

Product Overview

At last! Introducing our latest product from our review section. If you’ve made it to this point, then you’ll know straight away about this brand. This is because it’s the same brand as the first product. 

Now, why have we put this one at last? How is it so much different from the first product? Well, the obvious difference is that this product isn’t electronic. 

So, you’ll have to go through a more traditional way of measuring things.

The process of testing won’t be that easy when compared to the first product. But, that said, both the products follow the same accuracy of ± 6%. 

Thus, there’s a bit of win in both situations, right? Well, there’s a lot to discuss. So, let’s begin- 

As we’ve mentioned, it’s not going to be as easy to test this product out as the first product. This means you’ll need to wait it out for a bit. Other than that, the results seemed accurate and reliable all the time. 

But, the only drawback we felt was the process of experimenting because it took us some time to calculate the results.

As a result, you might have difficulty figuring out the methods. 

Even though we believe the results are accurate and reliable, the experimenting process makes us deduct some points. But we do believe this won’t be a dealbreaker of any sort. 

Many experienced reefers have praised this product as they know how to calculate the levels. So, if you’re not new to this, things won’t be confusing at all. 

So, we’ve shown the differences between this product and the first one.

Now, the choice is yours. Even though this one costs less than the first product, only you can decide what’s needed. 


  • Provides accurate results
  • Reliable and shows consistent results
  • Instructions are provided 


  • A bit expensive


Buying Guide

At times, the only thing that matters is clarification! We’ve dedicated an entire section separately to review our favorite 5 products. However, we believe that it isn’t enough to break everything down. 

Well, if you’re having a busy day, it’s quite normal you’ll go through everything at a glance.

That’s why you may miss out on key information here and there. 

Don’t feel bad about it; it’s completely normal. After all, we’re humans! That’s why we’ve taken the extra effort and added this separate section for your clear understanding. 

Here, in this buying guide, the key factors are discussed elaborately. Reading them will make you prioritize what you’ll need for yourself and what you don’t! 

Then, you can go on and select the best product. Let’s begin- 

Reading Time

You are reading. Time matters! After all, you don’t want to leave everything in the air and wait for your calcium levels.

Even though most traditional testing kits take less time to show results, there could be some annoying ones. 

And, if you feel like reading time is very important for you, then we’d suggest moving to an electronic one.

Here, you’ll get an instant result right away. So you won’t have to wait for a bit. 

Testing Process

Testing the calcium could be a hard task on its own. Here, you might need to worry about titration. Also, you’ll need to check whether the water is spilling. 

Here, the easier the testing, the better it’ll be for you. Hence, settle down for the products that don’t need additional steps in the testing. 

Just shake the vials, put them in the solution bottle and see the colors change up. That’s all needed, in the end. 


Yes, this is quite the issue. Suppose the color change isn’t noticeable. Then, it would be a large problem! Readability is crucial as you’ll judge the calcium level from it. 

Hence, it’s better if you have a product that shows readability large and clear. Here, the electronic testing kit does a great job as it shows the results on a large LCD screen without any complications. 


Well, nothing matters if you don’t have the right budget. If you have some extra money to invest, the electronic testing kit could be a great option.

And, if you want to save up on some cash, settle for something low. 

While many believe the cheaper testing kits provide inaccurate results, we believe it’s a misconception. So, set your budget and then make the purchase. 


Question: What should the level of calcium be in an aquarium? 

Answer: The calcium level inside an aquarium should be around 400-420 ppm.

If the calcium level deviates from this range, then the health of the corals and invertebrates will be at stake. 

Question: Will raising calcium levels lower the alkalinity?  

Answer: Yes, adding too many calcium supplements can lower alkalinity. This is because you’ll get calcium carbonate precipitation below the tank.

As a result, the alkalinity level gets lower every time you add in calcium. The same happens when you add in an alkalinity supplement as the level of calcium reduces then. 

Question: Should calcium levels be high in a reef tank? 

Answer: No, calcium levels should be in range on a reef tank. If the levels of calcium are too high, then it’ll cause precipitation of the alkalinity.

As a result, you’ll have a difficult time increasing the level of alkalinity. 

Question: Will calcium at extreme levels kill fish and organisms? 

Answer: Yes, calcium at an extreme level can kill the organism and fish inside an aquarium. So, it’s better to keep the levels in check. 

Question: What should the level of alkalinity be in an aquarium? 

Answer: The normal alkalinity level inside an aquarium should be within 142-215ppm. 

Final Words

Well, Reefers! It’s been an absolute pleasure chatting with you through this article.

We’re more than hopeful that the provided information will help you out at every step. 

So, head on out and get the best calcium test kit for yourself. And, if things feel a bit confusing, go through the buying guide. Here, the important buying factors will guide you to glory.