Calcium Reactors or Dosing Pumps: Choosing is All in Your Tank Personality

When it comes to keeping your tank’s parameters as steady as possible, kalk is king, then there are 2 main choices for adding calcium/alkalinity/magnesium additives your tank: calcium reactors and dosing pumps.

Each route has its pros/cons that I’ll outline first.

Calcium Reactors

Calcium reactors work by injecting carbon dioxide from a pressurized CO2 bottle into a chamber with coral skeletons and saltwater. The CO2 drops the pH in the chamber to around 6.5 so the calcium and other compounds in the skeletons dissolve and create a calcium-rich liquid called “effluent”. This effluent is then pumped in your tank, to keep your calcium and alkalinity stable.

What I like about Ca reactors:

1. They provide trace minerals from the coral skeletons.
2. They look really complicated (because they are) and have tubes, pumps and power cords coming out of the reactor. Reef Junkie, straight out of a sci-fi movie, cool stuff.
3. They are constantly running, so there are not spikes of Ca/Alk/Mg.
4. Mg media can be added to them so that they dose Ca/Alk/Mg all at the same time.

What I don’t like about Ca reactors:

1. They have lots of moving parts, so therefore lots of things to break, leak and/or go wrong.
2. They can drop your tank’s pH. (Kalk can counter act this drop).
3. They are expensive. A decent used setup will cost around $300 to start.
4. They can be hard to “dial-in” and require you to count bubbles, count drops, measusre your tank and make frequent adjustments until they are setup right.
5. They are big and bulky.
6. If you want to replace the media inside of them, you have to take the whole thing apart, replace the media, fill it back up with water, then dial it in all over again.
7. They take water out of your tank – i.e. water is pumped away from your tank, so if a water line leaks, gets disconnected or breaks, you’ve got the start of a flood on your hands.
8. They require a pressurized CO2 bottle that could turn into a rocket if it was knocked over and the regulator on them broke.

Dosing Pumps:

Dosing pumps are small mechanical pumps that pump Ca/Alk/Mg saturated liquid into your tank at specific rates, usually around 1.5 mL/minute. They are similar to dosing pumps seen in hospitals.

What I like about dosing pumps:

1. They are simple to setup. There is an inlet tube and an outlet tube, oh – and a power cord.
2. They are compact in size. You don’t need a lot of space to have a couple of pumps. The pumps I use are about 4″x3″.
3. When you run low on dosing liquids, simply remove the reservoir, mix up more and replace the reservoir. No re-dialing in needed.
4. They are very precise. You know exactly how much liquid per minute they are adding.
5. Easy to dial-in. You know how much your pump is pumping in per minute, you figure out how much Ca/Alk/Mg your tank goes through in a day, you know how much of the dosing liquid it takes to raise your tank a given amount of Ca/Alk/Mg, then you just have the pump turn on long enough to dose the amount of liquid needed.
6. You can easily spread out the daily dose of liquid needed so that your tank’s parameters are more stable.

What I don’t like about dosing pumps:

1. They don’t dose the trace minerals that the Ca reactors do. NOTE: There are dosing methods out there that do dose these minerals, but they are expensive and their value is negligible.
2. If your tank has high Ca/Alk/Mg demands, the cost of the dosing liquids can add up. (However, kalk will largely take care of your Ca/Alk requirements. On my tank, I dose 20 mL of caclium a day and I’ve had the same 1 gallon jug of ca supplement for 8 months).
3. You need a pump for each supplement dosed. Chances are, you’ll end up with multiple pumps.

How do you choose?

Choosing is as easy as knowing your tank personality.

Calcium Reactor: Reef Junkies

Remember that part of your tank personality is organizing your life around your tank. Since Ca reactors are complicated, take a while to dial-in and have to be dialed in all over again when the media needs to be replaced, count on dedicating a chunk of time your life to your reactor. I agree that once they are setup, they can largely be left alone, but when it is time to replace the media, get ready to dial them in all over again.

On top of that, part of showing off your tank to whomever comes into your house will be to show them this collassal, sci-fi looking thing with a pressurized bottle of CO2 sitting next to it! C’mon, that’s cool, right…? Surely your Friday night date will want to see your Ca recator! (See if adding it to your match.com page scores you any more dates and let me know)

Dosing Pumps: Reef Enthusiasts

You want your tank to look good, but you’ve got other things in your life as well. Therefore, it makes sense to have an easy to setup, easy to maintain, dosing pump adding Ca/Alk/Mg to your tank. Making up more dosing liquids is as easy as mixing up more liquid and refilling your reservoir. Done…and done…Onto the next thing!

Both calcium reactors and dosing pumps help your reef tank look great, and people take months to choose which route they want to go. When you know your tank personality, complicated decisions become easy.

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