By Bob Goemans
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Kalk King Doser

Manufactured by: e-Fins

A product review by Bob Goemans

Without doubt, an ingenious device! In fact, this review began in late 2013, far before it was purchased, ...when I decided to set up another small reef system, with one of its goals to automate the additions of Kalkwasser. Much research went into the wide array of equipment that could accomplish Kalkwasser additions. Bottom-line, a video at caught my interest, as it depicted a device that appeared to be so well engineered it could meet all my desires and possibly more for an automated Kalk unit.

When the product arrived, my new aquarium had already been up and running for several months and was using the e-Fins ATO float device to replenish evaporation, which is reviewed elsewhere on this website.

Upon opening the Kalk King (KK) box, found all its parts extremely well packaged. And since the KK is not what could be called a 'plug and play' unit, read through its 32 page instruction manual. Found certain portions of its text highlighted in yellow, with other text selections being 'bolded' red or black to draw attention to more important aspects of setup and operation. There's also a photo of each part of the system making it very easy to ID all parts, and therefore, properly install them.

Nevertheless, even though it's probably one of the better-written product manuals, it did not give an 'overall description' of how the KK functioned. Unfortunately it took much additional time/written questions to the maker to get answers to system operation that could have been avoided if it were mentioned in the instruction manual. This would have saved much frustration at certain points in the checkout of this equipment, simply because what I was seeing and thinking were possible system faults were really programed system responses to its overall functions!

Before beginning this somewhat rambling review, let me offer what I think should be right up front in the manual and that is an explanation of 'system operation' - "The KK's Computer Control Unit (CCU) automatically, every 2 hours, operates the mix pump for 10 minutes thereby thoroughly stirring the Kalkwasser powder in the holding chamber. When occurring, the CCU's LED lamp quickly blinks twice, repeating those 2 quick blinks for that entire 10 minute mix cycle. When that completes, the CCU allows settling of the stirred Kalk powder for 5 minutes, with it's LED lamp quickly blinking 3 times, again repeating those 3 quick blinks for that entire 5 minute period. For the timeframe between the automatic stirring and settling cycles, the mix pump turns on for 0.5 second every 8 seconds to keep Kalk powder in a slightly mixed state so as to prevent total settling of the powder. While in this momentary mix pump on cycle/stand-by mode, the CCU's LED blinks once every 10 seconds, and is constantly monitoring the float's on/off status. If the float is indicating the aquarium water level is fine as is, no Kalk solution or freshwater is added. If the CCU does sense aquarium water level is lower than what it should be, via float position, the CCU then checks to see if pH is lower than its user desired set point. If so, the CCU has the 'feed' pump supply small doses of freshwater about every 20 seconds to the Kalk chamber where its more clear upper Kalk solution flows via gravity to the aquarium/sump until the pH set point is reached (That would then have the LED blinking steadily until pH falls below set point) or stop flowing should correct water level be reached prior to pH reaching set point. If the aquarium still needed water after a pH limit was reached, freshwater only would then be added via the 'by-pass' pump until the float signalled the aquarium's correct water level was reached. As a safe-guard, the CCU will not allow any fluids to be added if the float sticks closed or open."

Moving on, ... after reading through all pages several times, and again looking at the on-line video, thought myself ready to begin its setup. 'Without' this above understanding of KK operation, began my checkout of the equipment by first wanting to test its two high quality check valves, one that connects to the outflow from its ByPass pump, and other to the outflow from its FEED pump. Wanting to simply test the seals in these check valves 'before' installing them, thought I would simply 'blow' through both valves in each direction to be sure there was flow in one direction, yet not the other. Could not get air through from either direction no matter how hard I tried.

Contacted the maker - was informed each has a little spring in them and it will take water pressure from the pumps to get through, and that the spring also provides a positive seal to prevent backflow. Very high quality check valves, yet nothing about this little spring and needing water pressure to operate correctly appears in the instruction manual.

Moving on, ... the placement of the KK acrylic reaction chamber, which holds one gallon of water/Kalkwasser solution, had to be placed on the right side of my sump due to the overall logistics of how my aquarium and sump were placed within the available space I had to set up the entire aquarium project. It would have been better if the KK reaction chamber could have fed its solution directly into the sump, but because the sump had three separate areas, and its far left area was where I wanted the solution to enter and be mixed via a small 2.5w pump before it fed through this area's lower opening into the center section of the sump, I connected a length of PVC tubing to the KK chamber's outflow tube and via gravity its flow, when needed, would cross the top back of the sump and drip into the sump's far left section. Said piece of tubing is not glued, as once every couple months the tube is removed, as is the Kalk holding chamber and cleaned with a long handle brush and some freshwater and vinegar, then reinstalled. Works well! Nevertheless, having its solution spill directly from the KK chamber into the sump or aquarium would be the preferred way to go!

Moving on, ... 'System Set Up' instructions has 21 steps and most have a photo of the item discussed and how it's attached. Nevertheless, think step 19 should be step 20, with 20 being 19. It just seems to be more reasonable the KK's CCU power switch is off and its two front dials are not on the zero positions, which is step 20, before the CCU's power adapter is plugged in, which is presently step 19.

Also, found step 21 somewhat perplexing, as it simply said to plug in the KK's pH probe power adapter if not relying on its batteries - period. Since the CCU depends on its float and the pH of the aquarium water to make a decision as to which is needed, having a programed pH meter and probe at this point in time would be preferable in my opinion before proceeding to the next set of instructions titled 'System Start Up and Functional Check.'

Therefore, decided to calibrate the probe before going on to the functional checks and mixed the supplied dried chemicals to make the two different pH solutions. Then removed the meter's batteries and connected the probe directly to the meter, and then connected its power adapter to a power source. Calibrating the meter was quite easy, and in fact, KK's high quality probe read exactly the same pH level when it was finally inserted into sump water that my PinPoint probe/meter read in my above aquarium! Keep in mind when calibrating the probe; the CCU's front slide switch is in the 'Live Probe' position - the right position. And when setting the CCU's 'Set pH Limit,' the slide switch is in the left position where a small black dial near it is used to set pH limit. But nowhere in the instruction manual did it say what position the slide switch should remain when completing these efforts and running the KK system.

Contacted the maker - was informed it did not make a difference, and the CCU would operate normally once these two parameters were set no matter what position the switch was left in, or even if the pH meter was turned off. Having that info in the instruction manual would have saved some time trying to figure out what was the final correct switch position!

Finally, the KK was up and running! Yet thought it odd that several times a day it would go into a 10 minute mix cycle of the Kalkwasser powder, then go into its 5 minute settling timeframe, but not add freshwater or Kalkwasser (even when pH was lower than the set pH number).

Contacted the maker - was informed mixing and settling cycles are on a fixed timer, i.e., every two hours, and during the time in between these cycles, if the float say's no water is needed, nothing flows into the aquarium. But if either 'is' needed, it's added as programed. That would have been nice to know prior to running the system!

The next 'situation' I noticed was that the Kalkwasser powder was not fully mixing in the Kalk chamber, and was settling mostly to its side areas, even when the mix pump was running.

Contacted the maker - was informed its small pump was no doubt not at the angle it should be, and that was clearly mentioned on page 22 of the instruction manual under 'Operating Note and Trick,' item 8. Okay, I missed that, and also went back online to view the video as to how its mix pump was positioned. Then drained the Kalk chamber and moved its mix pump to the correct angle, which resolved this situation. Out of the box, the mix pump was not in its correct position, but missed that! My error!

Right from the beginning I had a problem with the KK float, as it appeared not to be telling the CCU that water or Kalk solution was needed. (Keep in mind here that the KK float is an identical copy of the eFins ATO float assembly and that the eFins assembly was removed and replaced with the float that came with the KK). When I had the e-Fins ATO replenishing evaporated water, the bottom of its float was about 1/3 inch above its most bottom stem area and never had any problems with it over months of operation, as water level was always maintained correctly. Therefore, I set KK's float level at the same depth of the eFins. What I found, after much frustration, was the KK's float only seemed to be capable of connecting with the CCU if its float bottom was 'very' close to the bottom of its stem, about 1/8 inch, maybe less. Once that was adjusted, the KK was up and running - at least occasionally. I then began experiencing many system shutdowns where the CCU indicated that the float was stuck 'off' and had its LED blinking 5 times, which indicates a float stuck off position. Lost count of how many times I adjusted the float and restarted the KK.

Contacted the maker - was informed the magnet that holds the float assembly to the side of the sump has to be at the highest point of the 'L' shaped bracket that holds the float. It was and continued have more system stoppages!

Contacted the maker and explained I was tired of adjusting the KK float, and would replace it with the e-Fins float assembly, which at that time was gathering dust in the garage.

Contacted the maker and notified them this seemed to fix the sticking float problem, with the eFins ATO float set at the same depth it was when simply replenishing freshwater.

To make a long story quite short, one that included other thoughts as to how to rectify the KK float problem, the maker finally informed me they had now found that some of the KK floats had a magnet polarity problem with their supplied 'L' bracket, whereas eFins ATO floats all had a perfect match. Therefore, the change to an old eFins ATO float assembly resolved the KK float sticking problem, but not without 'much' frustration!

With the KK now running smoothly, now heard one 'quiet' evening in my office the mix pump briefly going on about every 8 seconds while the system was between its main two hour cycles and, 'still' not yet fully knowing the KK actual operating sequences, thought that odd - why is the mix pump working for a split second once every 8 seconds?

Contacted the maker - was informed that is normal to ensure the Kalk powder is always somewhat in suspension and does not fully settle into a hard lump. This means the mix pump will operate 0.5 second, once every 8 seconds when the mix and settling cycles are 'not' functional. Another 'situation' resolved! But was finally putting 2 + 2 together.

Contacted the maker and described how I thought the system operated/the description you read in the beginning of this review, to which he replied - "WOW, you got it totally correct!"

I've also experienced the LED light not coming back on after the 5 minute settling function. During this unlit timeframe noticed the pH meter was still reading the pH, yet the mix pump was 'not' doing it's on for a 0.5 second every 8 seconds and Kalk powder had settled completely.

Contacted the maker - was informed the light can represent either the activity of the mix pump or feed pump. And that it was showing the status of the feed pump, which if the float switch is no longer low, the LED will not light up.

This led me to believe that in time the LED would go back to normal as soon as the float goes slightly lower, but was not sure at this point in time. But on one occasion while looking at this 'no light' situation after a few minutes, the mix pump began its 0.5 second function and began its once on every 10 seconds function. So I presume this aspect self corrects itself in a short timeframe thereafter.


Because KK engineering is so vast, normal programing of CCU operation can easily be changed to 'adjust' various aspects of it's programming to suit the needs of different size aquaria (20 - 500 gallons) along with their environmental need, e.g., stir time can be changed; Kalkwasser output drip rate can be changed; mixing and settling timeframes can be changed; the float switch can be disabled to have the unit 'only' supply Kalkwasser solution 'X' times per day while a separate ATO system supplies freshwater as needed: and if the user messes up any additional programing, there's also a simply way to reprogram the unit back to its original factory settings. Quite amazing! Additionally, the instruction manual has some troubleshooting and maintenance comments that can be helpful.

All in all, consider the Kalk King Doser an extraordinary piece of equipment! Far more cost effective than a calcium reactor and one that only utilizes 5 watts of electricity to accomplish all its functions!

Nevertheless, I would highly recommend some changes to its instruction manual, and more prompt and detailed answers to questions that can arise during set-up. But overall, once up and running correctly, it's a worthwhile investment for those wanting better water quality/pH, calcium and alkalinity control for their reef aquariums.

Finally, I've asked the maker what comments/questions have been received from those who have purchased the KK, and it appears system setup, operation principal/system functions, and pH meter settings are the majority. I can fully understand and that is the reason I've included similar 'aspects' in this review, which I hope is helpful. Furthermore, would like those having this product to contact me directly with their thoughts/questions via the 'Contact' heading on the right side of this websites menu. Could be I'll add to this review those comments if helpful. As to replacement parts, they are available at And before I close, I'm informed the next model KK, coming mid 2014, will have some major advancements made to its mix pump architecture.

Addendum Mid-2014

2nd Kalk King generation model arrives! - This 'major' advancement has the hard to reach Kalk mixing pump now mounted on 'top' of the mixing chamber cover with its long stirring rod through the cover and its impeller reaching the bottom of the chamber. The new model also provides a simple plug and play mode that does not require a pH controller, and allows for various dosing capacities and schedules all capable of meeting your exact needs!

A rehab kit is available for existing Kalk King 1st generation units. Contact Kalk King for information as to how to take advantage of this upgrade, as I did and my Kalk King now operates flawlessly! I could not be more pleased with my Kalk King!

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