How To Dose Magnesium and Calcium: Kent Nano vs. Brightwell Aquatics


Kent Nano Reef Pats A and B vs. Brightwell Calcium, Magnesium and KH

For my first product review, I’ll be putting the Kent Nano A-B solution against the Birghtwell Aquatics liquid doses (Magnesium, Calcium, KH Buffer). (Yes, some links are affiliate links and I may get a small commission.) I figured this a great first review because there is not a single item reefers can spend more money on than the search for the perfect dosing solution. Yes, you get more control making your own two-part, like the BRS two-part solution. But that is a lot of work for a beginner or someone who just has a nano reef. The pre-made solutions are just simpler, don’t require a lot of effort, and are pretty much just “pour-and-play.” And in this hobby (as with most others), the easier something is to do the more likely you are going to do on a regular basis. That’s extremely important with reef tanks because stability—in parameters, trace elements, etc.—is the key to a successful tank.


Kent Nano A-B Solution


The biggest positive of this product is that it claims to have every trace element you need for your nano reef to thrive. It also calculates the measurements for you, telling you exactly how many drops to add daily. One downside, however, is that it is unclear just what elements are being added. A basic tenant of reef keeping is to never dose anything you cannot test for. Without knowing what is going in your tank, it is impossible to determine which parameters are off and which are correct. Having said that, I used Kent Nano A-B solution for the larger portion of two years when first starting out. (I say larger portion because I was never careful enough to make sure I added it every day. As I said, the easier things are, the more likely you are to do it. In my case, if it is something else I have to add to my already over-stuffed day, chances are it will fall to the side. This is why an automatic dosing pump is a great solution. More on that in another post.)


Without being able to measure the increases, the only analytic I could use to gage how this supplement helped (or hurt) my tank was through the naked eye. Results were sporadic. Sometimes my softies looked thriving, other times, those corals appeared to be dying. Without being able to test all the various parameters, it was impossible to pinpoint what exactly was causing my tank to thrive and what was causing its failures.


Brightwell Solutions


Brightwell’s products make up for Kent’s biggest downside: you know exactly what you are putting in. With the Magnesium solution, you know you are adding Magnesium. With the Calcium solution you know you are adding calcium. You can (and should) dose each solution and test the next day to see what effect, if any, it had on your system. The downside, however, is Kent’s strong point. With Brightwell, you have to do the calculations yourself. You must dose for a few weeks to determine how much of each element your tank consumes and determine the appropriate amount of daily dosages. It is not exactly “pour-and-play” like the Kent solution.


Which Works Better


The proof is in the pudding. You need only look at the numbers to see the final results. I keep a log of my parameters (something every serious reef keeper should do). As you can see from the below chart, while I was dosing with Kent, there was no improvement in calcium, alkalinity, or magnesium—the three elements I tested for. (The yellow highlighted rows are the days I tracked using the Kent solution.) When I switched to Brightwell, I first dosed Magnesium. It took just 5 days to elevate the Magnesium level from 1,050 parts-per-million (ppm) to 1440 ppm (the ideal ppm is about 1300-1400 to mimic natural seawater). I started with Magnesium because if you have a low magnesium level, dosing calcium will be almost meaningless. Without the proper magnesium level, the calcium will be consumed by the system.



Highlighted rows show parameters using Kent.

After I raised my magnesium level, I began to dose calcium. There were similar results. Careful not to shock the system, I dosed only 10ml per day. Every 10 ml raised the calcium by 100-150 ppm. In a matter of 4 days I went from 320 ppm to over 400 ppm.


I haven’t started the KH buffer yet (I don’t need it; my alkalinity is at 12dkh) but I hope to get similar results. I also didn’t want to test multiple solutions at once because I wanted to do a true scientific method. Isolate each variable to see how it does. Don’t worry, I’ll test the KH buffer and report back. (Subscribe to my mailing list to make sure you don’t miss it!)


Closing Notes


So far, the Brightwell products take the win. It is more work figuring out how much to dose but that is expected because each tank is different. While it would be great to say every tank just needs 10 drops of this solution to thrive, it simply cannot be done because some tanks may be overstocked while others under stocked. You need to see how much each element your specific system consumes in order to bring the levels up to thriving. Now, Brightwell does provide a formula to help you figure out the general dosage but that formula suffers from serious mathematical errors. And Brightwell does make it’s own A-B solution. In my book, however, I’d rather know what exactly I am adding to the tank so I can test for each element and isolate the variables.


Hopefully this review helps you save money on your journey to reef perfection. Questions? Leave them in the comments or feel free to contact me!


Happy reefing!

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