How To Choose & Set Up A Dosing Pump
In a reef aquarium, elements and nutrients corals and invertebrates use to survive must be replenished. The rate these elements and nutrients are depleted varies from tank to tank based on the organisms inside. If a reef aquarium is fully stocked, it may need to be replenished daily.
Hobbyists sustain these elements and nutrients using a variety of methods including water changes, calcium reactors, and dosing a variety of liquid additives. While water changes are easy and provide the exact ratio of balanced elements a reef tank needs, this doesn't suffice for most aquariums containing corals. Calcium Reactors work great for calcium and alkalinity, but you still have a variety of trace elements and nutrients to consider. That leaves us with liquid additives which are the most common way hobbyists maintain their reef aquarium's water parameters.
Some additives can simply be measured and added to the aquarium manually but when the tank demands daily supplementation, it's time to consider a dosing pump. A dosing pump is a peristaltic-style pump that can deliver precise amounts of fluids into your aquarium automatically. They operate using 1/8" - 1/4" diameter tubing and are designed for metered dosing at intervals, not a constant pumping action like your typical water pump.
Step #1: Choose Your Pump
There are a variety of different dosing pumps available. All perform the same basic duty of adding fluid to your aquarium at a safe, slow rate. The major differences between them are whether or not the pump can be programmed and how many pump heads are included in a single unit. Each pump head allows for a separate additive and you cannot deliver two different additives using a single pump head.
Most modern dosing pumps are programmable meaning you can program them directly to deliver a certain amount of fluid on a schedule; set it up once and the pump follows that same dosing cycle every day/week. There are also more basic dosing pumps like the BRS Two Part Doser that will need to be connected to a 24-hour classic timer to run a daily dosing cycle.
Within that, you have the option of single-channel, dual-channel, and even quad-channel dosing pumps which directly refers to how many additives you can dose with a single pump. Quad-channel pumps have 4 separate pump heads which mean 4 different additives while single-channel pumps only have one.
Which dosing pump is right for me?
The popular BRS dosers are your most basic option, all of which will require a classic timer to run a daily schedule. The pumps don't have any sort of ON/OFF switch or built-in programming. You have to set them up to have the timer run each for the necessary amount of time to deliver the amount of fluid you need.
Dosing pump technology has rapidly progressed in the last few years in that programmable single and multi-channel dosing pumps are pretty affordable. Kamoer is a popular brand that makes both Wifi and Bluetooth capable dosing pumps that can be programmed using your phone or smart device via an app. Bubble Magus dosing pumps offer digital programming using an onboard LCD screen.
Red Sea recently released the ReefDose which is quickly become a hobby favorite because it can be programmed via their ReefBeat app and operates with extreme precision.
If prefer to stick to high-end equipment, the Neptune Systems DOS and GHL Dosers are highly-regarded as some of the most advanced and capable dosing pumps on the market. When connected with the respective aquarium controllers, these dosing pumps provide the user with capabilities like setting up an automatic water change or having your tank's measured water parameters trigger and adjust your dosing.
Step #2: Get Your Tubing & Accessories
Most pumps will include some length of tubing but this is certainly the most important accessory. You need the tubing to run from our additive containers, through the pump, and then into your tank. Measure the distances from where everything is going to be mounted and be sure you have more than enough tubing. Colored tubing is great for multiple channel dosing because you can color-code each additive so you know what each line contains at a glance.
A dosing tube holder is quite handy for mounting the tubing to your sump or aquarium wall. It keeps them organized, out of the water, and prevents back siphon
Dosing containers or reservoirs are simply containers designed to hold your additives. They typically are clear or have a window so you can see how much additive is left inside, some are even marked with measurements. They will have a secure tubing connection as well and are much cleaner and more organized than a bunch of bottles under your tank.
Of course, the last thing you need is all your additives. Remember, only one dosing pump head per additive, and never mix additives. You will need individual lengths of tubing for each of your different additives.
Step #3: Mount the Pump and Attach Tubing
A dosing pump should be mounted up away from moisture and salt spray. Some pumps come with mounting holes or offer a separate bracket or shelf while some just need a flat surface to sit on. You want the pump itself above the water line and additives to help avoid siphon issues.
Setup the pump according to the manufacturer's instructions. It's best to cut and fit all your tubing as well. Be sure you're not cutting the tubing too short, you don't want any kind of pressure on the fittings and connections. A little longer than required is smart and be sure to route it through any channels you need, essentially cutting it to be as needed for final installation.
Mount your dosing containers but don't fill with any additives just yet. You will need to complete the calibration in most cases which is best done using some RO/DI water. So wait to actually fill with additives until after you have calibrated and programmed your pump.
If you are simply attaching the tubing directly to your additive bottles, just cut it to length but don't connect it. Using a length of 1/4" rigid acrylic tube inside the additive bottles can help you always pull fluid from the bottom of the bottle. Just connect your dosing tube on one end and drop the rod into your additive bottle after you have programmed the pump.
Step #4: Set the Dosing Schedule
Now the time has come to set up your pump. Each dosing pump is a little different in the exact setup but most will require some kind of calibration. This involves pumping RO/DI water through the dosing pump line to see how long it takes to move 10mL of water. This will essentially give you the exact rate of flow which will be dynamic based on your particular lengths of tubing.
For example, if it takes 20 seconds to deliver 10ml or water, that would be 0.5 mL/second or roughly 30mL/minute.
After calibration, you can program each of your dosing heads to deliver the particular additives you need. This is going to vary drastically from pump to pump in terms of the exact approach. Some pumps have you enter the total daily amount and how often you want it dosed. Others will ask for how much fluid for each dose. It just varies and always be sure to follow the instructions carefully.
Step #5: Test and Monitor Water Parameters
Once you have your schedule set up, do a trial run before applying the system to your tank to verify your programming.
- Fill your dosing containers with the intended additives.
- Place the end of each dosing line into a graduated cylinder or container.
- Allow the pump to cycle and verify the pump is delivering the correct amount of fluid based on your programming.
After you have verified the pump is operating correctly, attach the dosing lines to your aquarium and let it dose. Test your aquarium's water parameters closely for the first few days/week. Of course, pull the doser offline should you see your parameters spike and correct the program. It's a good idea to verify the programming as outlined above every time you change the settings.