Quick question about adding more nutes

Is it okay to simply add more nutes into water that's already in my rez? Or do I need to switch it all out? After changing the water last week, I am not confident I can pull it off again without hurting my plants lol. As the roots are getting incredibly long now and tangled with my feeding tubes.

Time to loose the feeding tubes if the roots are hitting the res if in DWC.....or are you running aero?

Dont ever add straight nutes to the res, mix them up in a gallon or a couple gallons of water and then dump it in, PH after that.

youre not supposed to add more nutes into your res without a full water replacement

there is no way to determine what nutrients the plant has absorbed and what it hasnt so by adding more nutes you can cause unsafe levels