CaCO3 or crushed coral into CA reactor? PH-controller?

[sasa311]

I've just bought a Ca reactor. My question is what should I take into it?
I saw crushed corals in most of them on the internet but my LFS says it is not good, I must use calcium-carbonat because crushed coral may contains Phosphats...

What should I use?

My other question is can I use it without a PH-controller?

 

[Aaron M.]

If you can get pure CaCO3 then that good to use but crushed coral is CaCO3 but I guess it may contain some phosphates.

You do not need a controller. Just a monitor is good enough to measure either the effluent from the reactor or the tank water. The controller shuts off the CO2 once the the pH gets too low, but the CO2 should be just right so that the pH level doesn't drop too low.

 

[sasa311]

well, thanks
Anyone else on the same oppinion?