When I first started keeping reef tanks 20+ years ago I dosed a two part solution for calcium and alkalinity supplementation. I figured out what I needed to add and dumped each solution in manually at different times during the day. Was it a pain in the ass? Yes, but reliable automatic dosers back then were just not available.


Eventually, I purchased a medical grade dosing pump but that proved to be unreliable, leading me to switch to a calcium reactor. The calcium reactor served me very well over the years since it was pretty much a set it and forget it piece of equipment. Every six months I would change out the media and maybe 1x a year I would re-fill the C02 tank.

Time to Reconsider Dosing

However, the reactor did lower pH due to the injection of C02, requiring me to use a kalk reactor to boost pH, a pain since I had to deal with another piece of equipment and more maintenance. Ultimately, I felt it was time to reconsider dosing since the technology on that front had advanced significantly over the years.


I researched a couple of different options and sought feedback from some fellow reef keepers to get their take on what they liked and didn’t like about the units they owned. Armed with this information, I settled on the GHL Doser 2.1 SA, which has four dosing channels.


GHL Doser 2.1 SA

GHL Doser 2.1 SA: Key Features

  • Built-in Wifi. No need to plug in an ethernet cable to connect to a network
  • Ability to access the doser remotely via the myGHL cloud service
  • Built-in temperature port and level sensor port for automatic top off devices and small volume automatic water changes
  • Doser can be expanded with the use of upgrade kits. So a 2 or 3 pump doser can be expanded to a 3 or 4 pump doser. You can actually have up to 16 total dosing pump motors run off of one standalone GHL Doser 2.1 SA or the ProfiLux 4 controller
  • Fluid monitoring feature, which automatically calculates the approximate number of remaining days before a container runs dry
  • Full 2 year warranty

Ok, so what are my personal observations of the doser? First of all, I find the unit especially easy to use. There are buttons on the front of the doser that can be pressed for manual dosing or you can use the app to do the same thing or check to see how much solution you have left.


GHL Doser 2.1 SA


The online interface that accesses the cloud is intuitive as well. You can opt for preset automatic settings or set up your own manual schedules if you want to dose during a specific time period and/or on certain days.  Another really neat feature is the blinking GHL logo at the top of unit.  A blue/magenta pulse of light means the unit is operating correctly while a yellow pulse of light means it is time to refill your dosing containers.  There are other light cues as well.

The Bottom Line

Overall, I have been using the GHL Doser 2.1 SA it for a few months and I couldn’t be happier. Talk about set it and forget it! An extremely reliable unit capable of precision dosing. What more could you ask for.


For more information on this doser, please visit the GHL website.




If you are looking for additional insights and information, please explore my many other reef tank and SPS related articles as well as my book, A ReefBum’s Guide To Keeping an SPS Reef Tank: A Blueprint For Success. And you can see all of my reef tank videos online now as well as my Live HD Webcam.


Happy reef keeping!


**Disclosure of Material Connection**
This is a “sponsored post.” The company who sponsored it compensated me via a cash payment, gift, or something else of value to produce it. Regardless, I only recommend products or services I use personally and believe will be good for my readers. I am disclosing this in accordance with the Federal Trade Commission’s 16 CFR, Part 255: “Guides Concerning the Use of Endorsements and Testimonials in Advertising.”