Indoor How early can I add Earth Juice Catalyst and cal/mag

[Gage]

So last grow I had a cal mag issue with the RO water.

This round i plan not to have this issue by adding a half teaspoon of cal mag and a teaspoon of EJ Catalyst to a 2 week old plant... Is this safe?

I just bought a air pump/air stone and I have it bubbling right now for tomorrow. So am I good or should Pitch the water and get another gal and don't add anything to it or add just one or the other.

Any help greatly appreciated.

 

[Gage]

bump

 

[Gage]

thank you sir