AndyBotwin
Weed Whisperer
fwee, in my experience autos tend to be more prone to ca/mg deficiencies than photos. Then you have a lot of LED growers here, and those lights seem to make the plants hungry for it. On my current grow with HPS, I did not add any extra ca/mg to start. About 3 weeks in, I saw a few brown spots and light green streaks forming on some lower leaves which appeared to be a very early mag deficiency. I started adding 4ml ca/mg to each feeding and I have seen no further issues. So you can definitely take a wait and see approach if you stay on top of things.