Kalkwasser Reactor concerns

[bioteacher]

Looking for opinions/experience here. I am thinking of adding a kalkwasser reactor to my 125g reef, but I have some concerns. I was thinking of the Two Lil Fishies reactor cause I don't want to spend $200 or more like most other reactors. Wondering if anyone has any experience with this product.

 

[bioteacher]

One big concern is an overdose of kalk. Would be pairing with a JBJ ATO and a 5 gal top off container. I can handle 5 gals overflow in my sump if it is just rodi but 5gal running through a kalk reactor would probably be a disaster.