If you can it is the best way to go. You hear all the time that if you do you need lots of extra CalMag and that's not true. I never had it for 10 years of doing DWC with the old AN nutes and never once saw a real Ca deficiency. I always used a bit of Epsom salts but it doesn't supply Ca. I even made my own calcium nitrate using marble chips and nitric acid and didn't see any difference. I now use CalMag at about 1/4 of what's recommended just to be sure.
Seems like the last few years all the nOObs think CalMag is the magic bullet like penicillin was when it first came out. Not so.
Any quality nute or soil/soiless blend will have more than enough Ca for a first grow. Reusing that mix may need supplements but if you are using soil then add a bit of domalitic lime or gypsum to it and you're covered.
Observe your plants. Get the feel for when they are happy or wanting something. You saw your plant get perked up when you watered it. Was that just because it was thirsty or did it get something it lacked? It's a bit like plant-whispering and it takes a lot of careful observation and experience to trust your instincts but it works.
You can't take two different plants or even the same strain grown from seed and use them to experiment with. They need to be clones from the same mother that have identical growth characteristics but have one thing different that you do to them to see if that one thing makes a real difference. That's the basis for any real observation that means anything. I've done a lot of those over the years directed by my training as a chemist. To do it right you need to have it happen every time as in reproducibility of the same experiment.
Just growing the plants is fun enough so everyone should just relax as they aren't any harder to grow than tomatoes!
... Some guy told me it was going to be easy..HA HA I'm sure he didn't do right!
