I'm currently think of getting either or both of these gadgets. Money is no matter in the decision since I found a good Calcium Reactor to handle my 130G system [90G Tank, 20 Sump, 20G Refugium] for around $ 170.00 [Saltwaterconnection.com if you are interested, and NO I do not work for them or get kickbacks, just passing the word on a good deal]. Just remember that the prices are in Canadian denominations so the price is going to look like $ 249.00 but it should be way less [when converted to US dollars]. the other component I can get from Stoneyreef.com, which is the Kalkwasser reactor, and it goes for $ 120.00 and $200.00 for a package deal; same as with saltwareconnection, I do not work for the site, I actually found it while looking on eBay for an auction on the two and the kalkwasser reactor that I found mentioned the site on the auction information. Anyway, I already purchased a CO2 Regulator with Solenoid, Needle Valve and Bubble Counter, so i definetly got to get the CO2 bottle and the Calcium Reactor. But I read somewhere that he two [calcium and kalkwasser reactors] can actually complement eachother and thus hold the parameters more stable. Please post any replies that might help in my desicion. Thanks.