Take an additional 10% OFF Livestock with code: CYBER10



Magnetic Kalkwasser Mixing Reactor - IceCap

IceCap  |  SKU: Y139020


Simplify & automate the addition of calcium hydroxide with the IceCap Kalk Mixer! 

The IceCap Kalk Mixer is a dedicated reactor for mixing calcium hydroxide (Kalkwasser) solution to ensure maximum concentration with each dose to your aquarium and eliminates the need for frequent manual mixing.

A clever magnetic mixer means no more pesky powerheads to clean and replace frequently. The intelligent design makes maintenance a breeze, and the slim profile allows for easy placement under your tank and integration with your existing ATO system.

Available in 3 Sizes:

Small - Ideal for Aquariums up to 100gal
Footprint: 5.7" x 5.7" | Body Diameter: 5" | Height: 25" | Holding Capacity: ~1gal

Medium- Ideal for Aquariums up to 200gal
Footprint: 7" x 7" | Body Diameter: 6" | Height: 25" | Holding Capacity: ~2gal

Large - Ideal for Aquariums up to 300gal+
Footprint: 9" x 9" | Body Diameter: 8" | Height: 25" | Holding Capacity: ~3gal


  • Adjustable speed magnetic mixer
  • Solid PVC and acrylic construction
  • Compact profile easily fits under your tank
  • Reactor vessel detaches from base for easy maintenance
  • Push-fit tubing connectors
  • Convenient quick-fill cap for mess-free Kalkwasser addition
  • A sealed airtight environment preserves solution potency
  • Gravity drain design ensures reliable performance


Using Kalkwasser to supplement the aquarium with calcium and carbonates is one of the most efficient and economical methods and has been used successfully on reef aquariums for many years.

The Kalkwasser powder is relatively inexpensive, super-concentrated, and mixed into your top-off water. Additionally, the elevated pH of the resulting kalkwasser solution and CO2 reducing properties help to maintain a more desirable and stable pH of 8.3 inside your tank.

The IceCap Kalk Mixer will ensure maximum concentration with each dose to your aquarium and reduce the need for frequent manual addition and mixing of the solution.

How It Works

Connect the IceCap Kalk Mixer to any freshwater reservoir using an Auto Top Off unit or dosing pump. Next, Kalkwasser powder is added to the mixing chamber via the handy quick-fill cap. The adjustable speed motor should then be attached to a timer or controller and set to periodically mix the solution inside the reactor a few times per day.

The freshly mixed and highly concentrated Kalkwasser solution is pushed out and into your aquarium when fresh water is pumped from your ATO reservoir into the reactor.

When adding kalkwasser to any aquarium, it is best to use a pump with a slow flow rate. Due to the high pH of the solution, you must add kalkwasser slowly and in small amounts, typically multiple times per day. Most ATO systems on the market will fit the flow rate needs of the reactor very nicely because of the small and frequent dosages of freshwater.


Once every two weeks, the kalkwasser powder in the reactor will need to be replenished, and thanks to the quick-fill cap, the process is painless and mess-free. The entire reactor vessel only needs to be rinsed out entirely once per month to dispose of precipitates and make room for fresh Kalkwasser powder.

Note: Kalk Mixer motor is unsuitable for continuous use and should not be run constantly. Necessary ATO system, calcium hydroxide (kalkwasser), dosing pump, and timer/controller are required and sold separately. Reactors are not submersible.


FREE Ground over $49 & Overnight over $399*

We offer competitive rates on aquarium supplies.

Reefer Rewards Points earned

Reedem points for discounts on Livestock and Supplies.

Split-Pay & Financing Options

We offer split-pay & financing options through Shop Pay.