Aquarium Dosing Pumps? What Are They For?

As your saltwater aquarium begins to mature and you find yourself looking at the corals more and more when you go to the fish store, you will soon be learning about ‘Dosing’.
When you first begin adding corals you will not notice any change in your water parameters, but as you add more and they grow, you will now have to look into this term ‘Dosing’.

I was just like you at one point and had no idea what dosing was, let alone what it would entail. It can be daunting for the beginner because it is yet another thing you have to learn to keep your aquarium healthy.

Aquarium Dosing Pumps are small fluid pumps that accurately add measured amounts of liquid supplements, foods, and trace elements to an aquarium. Controlled via timers or integrated electronics to ensure they dose the correct amount of fluid at the time specified by the user.

As corals grow, especially those that have a hard skeleton, they begin to consume Calcium, Magnesium and a thing called Alkalinity from the water.

The corals use these compounds to build their skeletons and there will become a point where your regular water changes will not be able to keep up with the coral’s consumption of these compounds. This is where you begin adding these compounds back to the water, also known as ‘Dosing’.

You now are faced with two options:-

1. Manually Dosing
2. Dosing Pumps

The type of dosing pump you look at buying can really make a difference to the health of your aquarium. Read on to find out more…

Are There Different Types of Aquarium Dosing Pump?

If you have read this far you probably getting ready for your first corals, or you are at the point when you are sick of manually adding 2 or 3 separate fluids EVERY SINGLE DAY!

To save our sanity and allow us to go on vacations again, there are two main types of dosing pump used in this hobby today:

1. Peristaltic Pump

2. Diaphragm Pump

Both have their Pros and Cons!

Diaphragm Aquarium Dosing Pumps

These types of pump are one of the most common among the beginners to dosing, as they are relatively inexpensive compared to their Peristaltic counterparts.

There is one main brand that is used over and over again because of its high quality and relative accuracy.
This is the ‘Aqualifter’ by Toms Aquatics.

Toms Aquatics Aqualifter
Available Hanging Bracket

A Typical Aqualifter Dosing Setup – MaddyP

The diaphragm pump works by moving rubber bellows back and forth in conjunction with a series of one-way valves. As the bellows are pulled open a one-way valve allows fluid to be sucked into the bellows (similar to taking in a breath of air).

As the bellows are then pushed closed a different one-way valve opens and allows that fluid to be moved out of the bellows/pump. As this is repeated multiple times a second,  it sucks up fluid from your container and transfers it through the pipe to the aquarium.

By controlling the amount of time the pump operates you can dose a set volume of fluid.

Most aquarists will set up an Aqualifter to a digital timer to be able to control the ‘ON-Time’ down to the minute. This works well especially for Nano Aquariums where the demand is too much for water changes to replenish yet not high enough where the Aqualifter is on constantly.

A Timer and Aqualifter is required for each compound to be dosed.


Inexpensive to Purchase and Setup
Easily adjusted to maintain consumption
Available mounting brackets to install Aqualifters out of the way


Can only dose fairly small amounts per minute
Diaphragms will need to be monitored and replaced to ensure accuracy
Regular calibration is needed to ensure accuracy
Diaphragms can wear out at irregular rates
Connecting to a controller will require using a power socket for each pump

Peristaltic Aquarium Dosing Pumps:

These are by far the most popular dosing pumps used by the serious saltwater aquarist. As your corals begin to consume large amounts of compounds every day, you need a very accurate and VERY reliable way to keep up with the demand.

Bubble Magnus Dosing Pump
3 Head Dosing Pump System

A Typical Dosing Pump Setup

Corals seem to become more temperamental the larger they become and a small lapse in their health can rapidly spread throughout a colony and kill it within days, if not hours. A more accurate way of controlling the compounds you dose is a Peristaltic Dosing Pump.

A peristaltic pump operates using a set of rollers that squeeze a silicone pipe as they rotate. As each roller begins to press on the pipe it creates a vacuum behind it as it moves along the pipe.

This vacuum sucks in a small amount of fluid from your storage container and is then moved through the pipe to the aquarium as more fluid is sucked in by each following roller.

The speed at which these rollers turn and the duration which they turn control both the dosing rate and dosing amount. This gives you much better control over how each compound is added to your aquarium.

There are several dosing pump brands that are recommended by not only myself but many, many experienced aquarists:

DOS system from Neptune Apex
GHL Doser Range
Bubble Magnus Doser Range
AquaMedic Doser Range
Kamoer Doser Range
ATI Doser Range

Each of these dosing units are proven technology from the biggest brands in the aquarium industry. They each have their own selling features and configurations, but they are all ‘Bullet-Proof’.


Super Reliable
Incredibly accurate
Can be set to dose dozens of times per day
Can be connected to aquarium controllers for ultimate automation
Some can warn you of low reservoir levels
Some can warn you if there is a dosing problem
More pump units can be added with ease
Easy to replace silicone tubes
Spare parts readily available


Expensive to purchase
Some units can only be used with the brand controller
Some units need to be installed with easy access for programming
Rollers need to be removed, cleaned and greased regularly
Silicone hoses can split without warning if not replaced regularly

You can view all these dosers HERE at
You will be able to find one that perfectly meets your needs.

I personally recommend the Bubble Magnus Range of Dosing Pumps

Aquarium Dosing Pumps To Avoid

There are some cheaper dosing units on the market that have been gathering popularity because of their cost.  However, I have spoken to many owners who have had their tank crash because these dosers stuck in the ON position and emptied an entire reservoir of compound fluid into their aquarium.

As more of these units are being purchased, more people are seeing their hard work destroyed. This does not happen to every aquarium owner but for the ones who have them fail, the results are devastating.

For the sake of saving a few bucks, it is not worth the risk to your entire aquarium. You are much better off to keep manually dosing until you can afford one of the dosing units mentioned above by the renowned equipment manufacturers.

Dosing is not one of those areas to skimp on the dollars. A small error with a doser can have a massive impact on your tank. Be patient, save your money and buy a good, well-reviewed doser! You will not regret it.

If you cannot find the doser on the big online saltwater retailers (I’m not talking eBay and Amazon here), there is a reason why you need to stay away from them. The big saltwater retailers only sell the best, most reliable equipment for good reason!

How Do You Dose An Aquarium Consistently?

Testing with good quality test kits, at the same time each day or week will give you an accurate reading of your corals consumption. Only when you have an accurate consumption value of each compound can you then set your doser to replenish this amount. Irregular testing will lead to irregular results and you will be forever chasing your tail.

You can view my Recommended Test Kits in this article HERE…

Calibration is a must for accurate, consistent dosing. Ensuring the amount that you want to be dosed is actually being dosed is critical. I calibrate my dosers every month and it is easy to do.

There are two ways to calibrate a doser:

  1. Place a measuring vial under the dosing pipe and catch the dosed amount at the time of dosing. Ensure it is the amount you asked for
  2. Run the doser for a set amount of time (eg: 1 minute) and catch the fluid in the measuring vial. This will then tell you the amount per minute your doser is supplying
Typical Measuring Vials

Adjust your doser to suit to ensure it supplies the correct amount.

Maintain your dosers and replace parts before they wear out. Whether you are using an Aqualifter or a Peristaltic Pump, always ensure you have spare parts in your home to quickly fix any problem. Murphy’s law will guarantee that your Alk pump will break at 1705 on the Friday of a long weekend!

Have spare diaphragms, rollers, grease, hose and motors available. They are relatively inexpensive to buy the spares, but it will save your butt!

Regularly clean your pumps. The build-up of grime, dust, and debris can really wear out the moving parts and slow down the pumping actions to give inconsistent dosages. Look after your dosers!

Magnetic Stirrer’s have been around in the science laboratories for years and are slowly finding their way into our hobby. A magnetic stirrer is a plate that your dosing solution reservoir sits on.

A small, sealed paddle is then dropped into the reservoir and is spun using magnetism from the plate underneath it. This is a great way to ensure the dosing fluids in your reservoirs remain mixed and consistent.

Just place each stirrer on a timer to come on a couple of times each day and your fluids will stay mixed.

Personally I just give my reservoirs a shake each day when I check on my sump, but for the Techie, these are cool pieces of kit!

You can find these magnetic stirrers HERE at

Further Reading

You may find some further help in these articles below. Please feel free to click away and read on!


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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