The best way to add calcium

[Tigger]

Has anybody used the Kent Liquid Reactor?
I'm trying to decided if it is better to use this stuff, or if it is better to use Kent Turbo Calcium and Super Buffer dKh and mix it myself. Would you say they are about equal? I am considering using the liquid reactor since you don't have to mix it and it is harder to overdose. John at J&L said that liquid reactor last for a long time. When you run out of liquid, all you do if add more water and you can keep on doing this untill all the stuff at the bottom is disolved. Has anybody done this? Is this stuff really soluble? Do you have to use DI/RO water to disolve it?

What do people think of the Turbo Calcium and the Super Buffer dKh?