Step 3 Explained: Aragonite Enhancers™ and Why Your Reef Needs Them

Introduction

It's easy to treat calcium, alkalinity and magnesium as three separate numbers, each with its own bottle and its own problem.

In reality, they hold each other steady.

Alkalinity buffers your pH. Magnesium helps stabilize alkalinity. Calcium can bind with alkalinity and help stabilize it too.

So when one runs low, the effect doesn't always stay with that one number. When magnesium runs low, for example, the manufacturer says alkalinity swings can happen more often, which can stress your aquarium.

That chain is the idea behind Step 3 – Aragonite Enhancers™ in the Reef Essential® system.

In this article, we break down what Step 3 does, the targets for your type of reef, what each Step 3 product supplies, and how to dose them in your tank.

What Are Aragonite Enhancers™?

Aragonite Enhancers is Step 3 of the five-step Reef Essential system. It supplies the elements corals use for calcification, building their skeletons from aragonite.

The Reef Essential® Aqua Care Guide™ sums up the three main components as CAM: calcium, alkalinity and magnesium. Strontium and barium are the minor components.

Corals absorb these elements from your aquarium water, which lowers their concentration. Step 3 puts them back.

The goal is strong aragonite rather than brittle calcite. The Guide describes aragonite as harder, denser and less susceptible to pH fluctuations. For the chemistry behind that, read The Science Behind Aragonite.

In the Guide, Step 3 follows Step 2 – Algae & Nutrient Control™. Once your nutrients are under control, it's time to dose the aragonite components. Like every step except cycling, Step 3 then stays in your routine for the life of your tank.

Calcium, Alkalinity and Magnesium Levels for Your Reef Type

The Guide gives CAM targets by the type of reef you keep:

• LPS/Soft Coral: calcium 420–440 ppm, alkalinity 10.1–10.5 dKH, magnesium 1255–1310 ppm.
• Mixed Reef: calcium 430 ppm, alkalinity 8 dKH, magnesium 1295 ppm.
• SPS: calcium 405–420 ppm, alkalinity 7.4–7.7 dKH, magnesium 1230–1280 ppm.

Notice the pattern. SPS tanks sit at the low end for all three, and LPS and soft coral tanks at the high end.

Pick the row that matches the reef you keep, and test against it.

The Aragonite A, B and C pages each give one wider band that covers all three reef types: calcium 405–440 ppm, alkalinity 7.4–10.5 dKH (132–188 ppm) and magnesium 1230–1310 ppm.

What Each Step 3 Product Does

In the Guide, Step 3 has one product for each part of CAM, plus one for low pH.

Aragonite A™ Calcium

Aragonite A supplies calcium, along with balanced strontium and barium.

The Guide says calcium, strontium and barium are used in countless biochemical processes. Together, they can improve the overall health of coral and help produce strong aragonite.

Aragonite B™ Alkalinity

Aragonite B is a full-spectrum buffer. It provides carbonate, hydrogen carbonate and buffers that supply alkalinity and help stabilize pH.

Here's why that matters. Carbon dioxide from respiration forms carbonic acid, which can slightly lower pH.

A buffer helps raise pH when it's too low and lower it when it's too high, relative to the Guide's reef target of pH 8.3–8.5.

Aragonite C™ Magnesium

Aragonite C supplies magnesium, plus sulfate and trace elements.

Magnesium is found in chlorophyll. That's why photosynthetic organisms in your tank use it, including zooxanthellae, coralline algae and phytoplankton.

It also helps stabilize alkalinity.

Bio-Kalkwasser™

Bio-Kalkwasser is for a different problem: pH that sits below the 8.3–8.5 range. It contains calcium, hydroxide and energy.

Kalkwasser helps raise pH by converting carbon dioxide into calcium carbonate. That can help both pH and alkalinity stability.

The Guide notes that pH can drop when your lights are off, because photosynthesis stops and carbon dioxide builds up. The manufacturer calls Bio-Kalkwasser a particularly effective way to reduce that nightly drop.

Why Calcium, Alkalinity and Magnesium Work as a Team

The Guide puts the chain plainly. Alkalinity helps stabilize pH, and magnesium helps stabilize alkalinity.

It calls that partnership a source of significant parameter stability. Your corals need that stability, and the Guide recommends keeping pH and alkalinity swings as small as you can.

That's why the manufacturer pairs the three. Used alongside each other, Aragonite A, B and C give your aquarium the major, minor and trace aragonite elements it needs.

Step 3 isn't about hitting one perfect number.

It's about holding all three steady, together.

There's one more reason to test all three: false uptake. A reading can look as if your corals used an element when it was lost another way. The Guide names alkalinity removed through pH fluctuation, and calcium bound by phosphate.

Chase those readings with more product, and you can end up dosing more than your tank needs. It's one reason Step 2 comes first.

How to Dose Aragonite A, B and C in Your Tank

The Guide gives Aragonite A, B and C the same daily band, 0.5–1.0 mL/day per 100 L (26 gal), set by how heavily your tank is stocked:

• Lightly stocked: 0.5 mL/day per 100 L (26 gal).
• Moderately stocked: 0.75 mL/day per 100 L (26 gal).
• Heavily stocked: 1.0 mL/day per 100 L (26 gal).

The other option the Guide gives is to dose as required to hold your targets. Test, then adjust from the result.

A few practical points from the manufacturer's product pages:

• Add each one directly into high water flow. Shaking isn't required.
• Each one can be used on a dosing pump.

Bio-Kalkwasser is dosed differently. You mix it with RODI water and add it through a drip system or a kalkwasser reactor. The Guide's drip solution per 100 L (26 gal) of aquarium water:

• Lightly stocked: 1 g per 4 L (~1 gal).
• Moderately stocked: 2 g per 4 L (~1 gal).
• Heavily stocked: 3 g per 4 L (~1 gal).

Only the clear top solution goes into your tank. Keep the white undissolved material out.

The manufacturer says not to dose more than 18 ppm of Bio-Kalkwasser per night in conjunction with existing calcium dosing. While you use it, monitor pH, alkalinity and calcium.

The free Quantum Aqua dosing app works out custom amounts for your tank. The full CAM table is in the free Aqua Care Guide, and every Step 3 product is on the Aragonite Enhancers collection page.

Frequently Asked Questions

How Much Does 1 mL of Aragonite A, B or C Raise My Levels?

The manufacturer says 1 mL per 100 L (26 gal) raises calcium by about 2 ppm with Aragonite A, alkalinity by about 0.1 dKH with Aragonite B, and magnesium by about 1 ppm with Aragonite C. The other elements in each bottle rise relatively.

What Water Volume Should I Use to Work Out My Dose?

Use the total volume of your aquarium and sump, minus everything that takes up space in it: media, rock, ornaments and so on. The manufacturer says this gives a more accurate dose.

What Should Strontium Be in a Reef Tank?

The Guide's target is 6–10 ppm. Aragonite A supplies strontium alongside calcium, and the Guide says to dose it as required to hold calcium at 405–440 ppm and strontium in that range.

Can I Mix My Own Calcium and Alkalinity Solution From Powder?

Yes: Aragonite A and B also come as powders. They aren't dosed 1:1: dose each powder to its own test result. The manufacturer's mix is 110 g per 1 L (0.26 gal) for Aragonite A Powder, plus ½ capful (5 mL) of the solution provided, and 69 g per 1 L (0.26 gal) for Aragonite B Powder. The mix may get hot, so the manufacturer says to wear protective glasses and gloves.

Do I Need Bio-Kalkwasser If I Already Dose Aragonite B?

The Guide recommends it for low pH. If your pH sits below 8.3–8.5, it suggests adding fresh oxygenated air and making kalkwasser part of your maintenance. If you do, the manufacturer recommends monitoring pH, alkalinity and calcium.