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Kalk Stirrer
Kalk Stirrer
Kalk Stirrer

Kalk Stirrer

$ 219.99

This product is experiencing very high demand.  We are allowing pre-orders and current lead time is approximately 1 week.  All orders shipped in order received. 

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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jeffrey o.
United States


super excellent

Alvin G.

Kalk reactor K1

Quality of the build is good. Setting up the reactor is pretty simple.

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