The Avast Marine Kalkstirrer is one of their best selling products and now with the DIY K1 kalkstirrer kit you can save 30% by doing it yourself. The Avast Marine DIY K1 kalkstirrer includes everything you need to start building a limewater doser for your reef. the 21 inch tall K1 has a footprint of 5.5 inches in diameter and it can reasonably dispense up to seven gallons of kalkwasser per day. The top-loading motor slowly spins a stirrer bar making sure that fresh water injected in the base of the reactor becomes full saturated with CaOH by the time it exits the effluent valve. The DIY Kalkstirrer should only take a couple of hours to assemble (longer to cure) and it is available now from Avast Marine for $139 + shipping.