Category Archives: Equipment

Elos Calcium Test Kit Review

Today we’ll be taking a look at the Elos Calcium test kit.

Every good aquarist knows it is vital to maintain proper levels of alkalinity and calcium in your reef aquarium. They are the key components for keeping corals healthy, happy, and growing.

Fortunately both can be measured easily and reliably with good quality test kits.

Now, when it comes to high quality aquariums and accessories, one brand name typical shows up in the top of the list: Elos.

The tanks made by this renowned Italian company are considered to be the ‘Ferraris’ of aquariums. And although they tend to be a bit pricey, many longtime reef keepers consider their test kits, fish foods, and other accessories to be top-of-the-line as well.

I myself find their phosphate (PO4) test kit to fantastic.

So I decided to give the Elos calcium test kit a try as well.

Elos calcium test kit

The Elos calcium test kit screams quality from the moment you open it up.

Everything from the logo-embossed glass testing vial to the color quick guide looks and feels top rate.

The kit comes with four reagents labeled A, B, C, D.

Three are used in the Approximation Test. And all four are used in the Precision Test.

The approximation test allows you to test your calcium to within 50 ppm (e.g. 50mg/l if you prefer metric) of it’s actual value.  Essentially it’s a quick check just to see if your calcium is within the recommended range of 380-450 ppm.

Then, if you desire a more accurate reading, the Precision Test allows you to read your calcium within 10 ppm.

I’m not going to go into details of performing the tests. There are already plenty of videos online that show it – such as this really nice done by Coralvue:

The key thing to know is this: in order to a Precision test, you first have to do an Approximation test. Otherwise you will use up the D reagent quite fast.

If you calcium tends not to shift very much, you’ll only need to do an approximation test once, and can then use it as the basis for all the Precision tests you do thereafter.

But if your calcium tends to shift quite a bit, you will have to do an approximation test before each and every precision test.

When I first saw that the Elos calcium test kit offered the choice of doing a quick, ballpark test or a more precise test, it seemed as though it would result in the use of less reagent … and therefore the kit would last longer and save money in the long run.

It turns out the opposite is the case.

As I said, it is a quality kit. The color changes are very easy to distinguish. And determining the calcium value from the number of drops required to reach the color change is very easy to do – especially since they provide with an easy to read conversion chart.

If you would like to try it for yourself, you can order one from most any large, online aquarium store such as Coralvue or Premium Aquatics …  or even from Amazon.

However, the reading I got from the Elos calcium test kit was the same as the reading I got from my Salifert calcium test kit – the brand I had been using up until now…

And the Salifert kit also measures to a precision of 10 ppm … while only requiring one test each time … using just three reagents … and for two-thirds the cost.

Oh, and both kits are good for 50-100 tests.

The bottom line: When I use up this reagents in the Elos calcium test kit, I will be switching back to the Salifert calcium test kits instead.

Both are great kits. But the Salifert kit is a bit quicker and easier to use … not to mention less pricey.



A Simple DIY Crab Trap for Catching Aquarium Pests

This DIY crab trap is a quick and easy way to remove unwanted nuisance crabs from your aquarium.

Unwanted pests such as gorilla crabs and stone crabs often make their way into aquariums as hitchhikers on live rock.

At first that my not be a problem. They can even serve as a valuable member of a clean-up crew while they’re small. But as they get bigger and their appetites grow, they will often start to eat corals or other more desirable members of your clean-up crew such as porcelain crabs, snails, and even small fish.

Many aquarists will spend hours trying to spear them with a skewer, or a pair of large tweezers. And some will even resort to spending anywhere from $15 to $50 on a pre-made pest trap.

Before you spend that much time or money though, there is an old reef keepers’ trick you might want to try first.

You can make a very simple DIY crab trap using nothing more than a small glass.

Here you can see the quarter-sized stone crab I caught an ordinary shot glass. Two tries with shrimp didn’t work. But it took less than 30 minutes to catch when I used a little bay scallop as bait.

shot glass crab trap
Small stone crab caught in a DIY shot glass crab trap.

A shot glass will work for small crabs that are about the size of a quarter or smaller.  For larger crabs you can use a bigger glass; one that is just tall enough so that the crab can’t reach the lip if it extends its claw.

The only thing you need other than a glass is some bait. Some people have success with a piece or raw shrimp from the grocery store. I tried shrimp twice but didn’t have much luck with it. On the third attempt to catch the little stone crab that was terrorizing my tank, I tried a small piece of raw bay scallop and it worked like a charm.

Simply place the glass in the bottom of your aquarium about 30 minutes before the lights turn off for the night, and lean it at an angle so the lip of the glass is resting against a rock.

Then place a small piece of the bait in the bottom of the glass and let it sit overnight.

The crab will climb down into the glass to eat the bait. But it won’t be able to get back out because the walls of the glass are too smooth for it climb up.

It make take a few tries, but a lot of reef keepers have had great success using this quick and simple DIY crab trap.


Seachem Denitrate: The Best Way to Make It Work

Seachem Denitrate – and Seachem Matrix – can do a fantastic job of helping to lower the nitrates in your aquarium. But there is one very simple, yet important step you must take in order to unlock their full potential.

It took me 6 months to figure this out. And once I did, the impact it had on lowering my nitrates was incredible.

Seachem Denitrate

First, let me point out that Seachem Denitrate and Seachem Matrix are both the same exact media. The only difference is the size of the pieces. Denitrate pieces are about the size of a pea. And Matrix pieces are about the size of a cherry.

The secret to making them work is placing them in the right amount of flow.

The instructions for Denitrate say it should be placed in flow that does not exceed 50 gallons per hour. And the instructions for Matrix do not say anything about flow. (They do hint that it is meant to be used cannister or drip filters, but that’s it.)

Having heard on some forums that Matrix is supposed to be better for lower flow applications, I put some in a media bag and dropped it into my sump.

Over 6 months it hadn’t lowered my nitrates one bit.

So, I did a little more digging and came across a thread on the Seachem support forums that changed everything. It contained a comment from a Seachem rep that said the ideal flow for Denitrate is 20 – 50 gph. And the ideal flow for Matrix is anything over 20 gph.

After spending 6 months in low flow in my sump, my Matrix was covered in crud. I could’ve rinsed it off and re-used. But, being lazy, I decided to just spend $10 on a new bottle of Denitrate instead. (I went with Denitrate because I figured the smaller pieces would provide more surface area for the nitrate-eating bacteria to grow on without taking up any additional space.)

This time though, I put it in a DYI nitrate reactor to make sure it got at least 20 gph of flow (35 gph to be exact).

What a difference!

Within 2 weeks my nitrates fell from 16 ppm to 2 ppm – and have remained there ever since.

It was so amazing and so simple. For more than 8 months I could never get my nitrates to stay below 12 ppm (they usually hovered around 16 ppm). Then, the simple change of giving the Denitrate media a bit more flow completely solved the problem.

And the best part is, it never needs to be replaced. Simply give it a good rinse every couple of months to remove any detritus that gets stuck on its surface and it will work forever.

So that is the key to getting fantastic results with Seachem Denitrate or Matrix: a minimum flow of 20 gph.

Oh, and if you use Denitrate, also be sure the flow does not exceed 50 gph. Otherwise, the water will pass through the media too quickly and the anaerobic bacteria living in its micro-pores will not have time to consume the nitrates.