a properly designed calcium reactor won't release too much CO2 into your tank and you'll end up with a higher pH rather than the low pH cheap/older-designed reactors cause.
as for the aquacare reactor it's a kalk reactor that uses CO2 to dissolve the lime in aquarium water instead of in freshwater like most reactors do. You can do the same thing for MUCH MUCH cheaper with a regular old Kalk reactor that's fed freshwater and no pH trouble caused by CO2. No fancy proprietary CO2 meter and there are lots on the market that are tried and true.
I'd recommend putting your $$ into a calcium reactor that's been around for a while and has good things said about it such as the Korallin, or a litermeter dosing system.
But that's just my opinion
