nitrogen deficiency curing?

I am using drop tests for pH so the pen cant be a problem. Im growing in soil btw.

Any chance you've recalibrate a ph pen if you use that method? They lose accuracy periodically. Mine was off a full point the last time I recalibrate. Thought I was using 6.6 and its was actually 7.6.

No way to tell how your growing, dirt, soiless, hydroponics? Ec values in dirt grows can be much higher than soiless or hydroponics. Find out your values for which way you grow and for what time period their in now. Give enough water to check your runoff values, ph and ec. If you haven't got an ec reader, I highly recommend one as sun, ph and ec are your most important factors when growing. Basically in that order cuz without good light your babies won't get the energy needed to grow well, improper ph either in your water going in or coming out of the planter stops the plant from taking up certain elements, which is ph lockout and too high ec coming out of the planter is ec lockout. So really, what is coming out of your planter is just as important as what your putting into it. Hope this helps you figure it out. Cheers

All you can do is start adding more nitrogen. The leaves won't fix themselves. Hard to try to diagnose without pictures of the plant, and leaves. Also good to calibrate your ph tool regularly. I do mine every other day. .1 off or more is a big jump. Hopefully this helps.