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Kalk Stirrer
Kalk Stirrer
Kalk Stirrer

Kalk Stirrer

$ 219.99

The new motor driven design of our stirrer silently and gently mixes your calcium hydroxide 24 hours a day. This ensures that you are always dosing the freshest possible kalkwasser to your system. Since the undissolved particles are always kept at the bottom and the clear liquid is always at the top, this is the safest available way to dose kalkwasser. The simple top loading design reduces the amount of time spent adding kalk powder to the reactor, which can be refilled in less than 1 minute.

No more powerheads to clean or replace, no more large vats of lime water taking up valuable space next to your tank. Once you try our stirrer you'll never look at kalkwasser the same again.

Note that our stirrers are non-pressurized chambers; water enters through a 1/4" John Guest fitting in the lid and gravity drains out into your sump through the 1/2" union barb fitting in the side. The lid is not fixed in place; it lifts off for quick and easy kalk powder refills.


 Technical Data K1 K2
Tank Rating 400 Gallons 800 Gallons
Output capacity 7 Gallons/day 14 Gallons/day
Footprint 5.5" x 5.5" 7" x 7"
Height 21" 21"
Power AC 120v 3w AC 120v 3w
Warranty 1 year 1 year


Click Here to Download the Manual

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Paul A.
United States

Kalk stirrer is awesome

Easy setup and well built. Another great product from Avast.


Great Reactor with one small modification

I run the Kalk Reactor using my Tunze ATO system. Initially this caused an issue with back siphoning because there is no backflow preventer included with the system, which is why Avast recommends using a peristaltic pump. This can be easily remedied by drilling a tiny hole in the clear tube inside the chamber about 2 inches from the top. I also had a second issue with the fluid not draining properly from the reactor, just make sure the outflow tube is above the waterline in your sump and you won't have an issue. Overall this is a great product, at a great value. I look forward to adding other Avast products to my setup soon.


Superb Reactor

I HAVE MY KALK reactor installed to my BRS peri pump, one line goes to the Avast kalk reactor and the other line goes into my Eshoops 5 gallon ATO storage container. It turns on and off with a float switch that connected to my Apex breakout box. Ones my water starts to evaporate and before it hit my TUNZE ATO optical eye my Float will open up and turn on my kalk reactor, my PH is always between 8.1 to 8.2.. I guess there many ways you can set it up but I find this way very easy and effective. Or like mentioned above

Jeff H.
United States

K1 - Smooth and Turbulent Seas

After researching several different products I decided to go with the K1 from Avast Marine. I placed my order Friday afternoon Pacific time and to my surprise, I received notice the next day on Saturday that my K1 shipped that day... Great customer service! When I received the K1 I will admit I felt the build quality would be better for the price I paid but I'm not saying it was bad, just not as polished I thought it would be. To elaborate, the milling around the motor cap was a little rough and I had to file down the set screw which holds the stirrer rod to the motor to prevent it from hitting the 90' elbow with every turn. Yes, I made sure the elbow was inserted as far as it would go. No big deal, but again I just expected a perfect product for the price. Rough seas ahead.... When I installed the K1 and plugged it in for the fist time I noticed the motor was louder than I expected and this turned out to be an issue. A couple of days later I noticed the motor was getting louder so I contacted Avast and sent them a quick 10-second video of the motor making the noise. Within two hours I had a reply indicating this was not normal and they would be sending a replacement motor/lid priority mail that same day. I simply can't say how hard it is to find companies that have this type of customer service today... Not only would I recommend this product to others, I will be purchasing other products from them in the near future.

Matt P.
United States

Kalk Stir K1 model!

Best Kalk reactor on the market in my opinion! Works awesome with my BRS peristaltic pump! HIGHLY RECOMMEND if you want to keep your PH, ALK and Calcium in check.