like others say, if the soil is dry, probably might want to give it a little bit of water. a little bit is like, 1/2 cup or less even. I dont know how big your plant is. It is all relative, that is why you may be getting what you feel are 'harsh' responses from some people.
If your leaves are droopy looking, water the thing.
I am not using any MG, just water that I balanced to 6.5(used to be a bit below because soil was a bit higher). I water maybe every day, with a tiny splash of my fixed water, when I wake up. If the plant is looking perky and nice, I might not water that day, and maybe give a bit more the next day.
(barely entered veg 2 days ago or so)
One thing I have read, try not to pour your water right onto the base of the plant, it may cause root rot(?). The area around it(some will go right onto the base, yes) should do fine.
Your gonna need to do your own research though man. I am just beginning my first time, and am in the middle of 3 books. Lots of reading, but the more you know, the better your stuff will be.