At the 2016 MACNA (Marine Aquarium Conference of North America) inventor and reef keeper, Jim Welsh, came out with a prototype of a product a lot of aquarium hobbyists have been dreaming of for years, an automatic blue alkalinity monitor prototype with four containers attached by tubingalkalinity monitoring and control system. While at the convention, Welsh showed that the device turned out reliable and accurate measurements. It is precise and accurate to +/- 0.05 dKH, which is a great deal better than the typical test kit. Neptune Systems acquired the rights to this product and the monitor will be integrated into the Apex aquarium controller. No official product announcement has been made so far, though, so the release date and other specifics are not known. Biologist and aquarist, Richard Ross, tested the monitor and was impressed by its ease of use and accuracy.

What is Alkalinity?

Alkalinity is a measure of how much acid (H+) it would take to lower the pH to a certain level. Total alkalinity (TA) is generally measured in aquariums. TA is the amount of acid it would take to lower the pH of the water to the point where all carbonate (CO3-2) and bicarbonate (HCO3) would be converted into carbonic acid (H2CO3). This basically means the acid needed to reach a pH in the 4 to 5 range. The main chemical responsible for alkalinity levels in reef tanks is bicarbonate, but carbonate, borate, silicate, magnesium monohydroxylate, hydroxide, and phosphate also contribute. Corals deposit calcium carbonate in their skeletons by using calcium and carbonate or bicarbonate. Because bicarbonate and carbonate make up the majority of the alkalinity, testing it tests for the amount of bicarbonate and carbonate available to your corals.

Why is Alkalinity Important?

Alkalinity is extremely important to keep at a proper level. Improper or unstable levels will quickly stress your corals and likely result in decreased health and growth of your corals and other invertebrates. Large changes in alkalinity is even one of the leading causes of mass death in reef tanks. At this time, the only way to test it is by using test kits, which is a tedious process that involves counting drops and watching for a color change. Because of this, a lot of people only test the alkalinity of their tanks once or twice a week. However, alkalinity is sensitive and can change in just hours, so more frequent monitoring is required for a safer tank.

The Apex

Neptune System’s Apex is a popular aquarium controller that already monitors and controls several important parameters in the tank including temperature, pH, and salinity. It can also be connected to control lights and pumps. It also allows users to control functions of their tank remotely from mobile devices. It even has custom features such as text and email alerts and feed modes.

How the Alkalinity Monitor Works

The monitor works by taking 1 ml of water from your tank at each testing time. It will then report the results via the Apex controller. Users will be able to adjust the frequency of testing, ranging anywhere from every ten minutes to once per day. This is beneficial because new tanks or tanks that have been changed or added to recently can be set toalkalinity chart in orange test very often and more stable tanks can be set to test less often to save the reagent. The monitor carries out the analysis twice each time. This will make certain results are accurate, especially if it is set to test at large intervals. After testing, some water will remain in the tube, so the first analysis will include a combination of water in the tank at present and stale water left in the tube from the previous testing. The second analysis is what you ought to really take as fact. It will need to be connected to a waste reservoir or drain to get rid of the tested waste water.


Alkalinity is one of the most important chemical parameters to keep stable for the well-being of tank inhabitants. It is also one of the fastest changing factors in aquariums, making it hard to continuously monitor and control. This is especially true for tanks with many fast growing stony corals. Being able to better monitor and control this will improve the stability of reef tanks, resulting in healthier corals. This monitor and control system is sure to be the next big thing in the reef keeping industry.



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Holmes-Farley, R. (2002, Feb). Chemistry and the aquarium: What is alkalinity? Advanced Aquarist. Retrieved November 11, 2016 from

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Unique Corals. (n.d.) In Facebook [Company page]. Jim Welsh alkalinity monitor (patent pending) first ever live demonstration. This is a game changer! Retrieved November 7, 2016 from


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