The EC is going to give you a more accurate measurement of salt content (the nutes). I think as long as you follow a good nutrient schedule and mix them in the correct order and measure correctly you won’t even really need to watch EC or even PPM after you establish a good baseline. It’s fun to watch how much they feed in later stages though. The seedling looks good. Just make sure to keep the water only up to the bottom of the net pot. The bubbles will spray up the nutes and the hydroton and starter medium will wick up to the roots. They start poking down fairly quick, but can take days. Once those roots settle in the nutes, they explode. You’re always gonna chase PH in a single bucket. Adding multiple sites and creating a larger pooled volume of water will create more stability of temp and ph.