Seems like your N is through the roof. And probably an issue you cannot fix without a meter.
What where you thinking, Dro with no meter?
Thats a no no.
I would suggest soil for future grows until you have all your ducks in a row prior to germination
But thats just my 2 cents. For now a simple flush of the res and refilling with balanced water is a great start. Get whatever it is out of your res thats causing this, and since you dont have a meter you really just need to start over with your nutes, or go buy a meter.
Your choice, but dont go trying to fix this blindly, without a meter.
That would be much worse then trying to do this in the first place without a meter
Best of luck to you though!