Help i need help

Good evening everybody I am a first-time grow in Hydroponics I'm noticing that my ppm's are going up after two days of changing my water my leaves are starting to turn a light green I think that is nitrogen problem can somebody please help ASAP

what are your ppms and ph? water temps? light green can be a nitrogen deficiency but also can be a lockout.

if ppm is going up your over feeding and they are drinking more water

Post some pics. Give some info.

I add pure ph water 2 days ago when i checked my plant pps this morning it reading 300