Yellow and brown bottom leaves, Nitrogen?

Just looking for advice on what to do!

It vegged for 2 weeks and has been in flowering for 2 weeks (since space is an issue it had to stay small) and the bottom leaves were slightly yellow but then almost overnight they turned bright yellow and now have some brown spots on the yellow leaves, what should I do? What is the cause (using jacks 10-30-20 fert for flowering). It's a CFL grow but until now it seems to have been happy (if growing slower than it should) Humidity ~40%, 12/12 light cycle, lights on top and two sides.

Is it nitrogen deficiency? I don't want to add more (since I just did two days ago) if its not the problem and I don't want it to burn.

Anybody? I want to verify this is nitrogen deficiency before I do anything and it's getting worse by the hour =(

Does it have drain holes? soil? pH?

Its inner leaves don't look happy too.

I would say it's a K deficiency, if the leaves just fall off without much wilting. Could also be a lockout of K, from too much Ca. Are you using calmag and tap? I have a small 1 week ved maui plant that did the same thing 2 weeks in flower. The K spots appeared on a few leaves after they turned yellow like yours.

It does have drain holes, ph is 6.5, I am not using cal-mag and tap.

I hit it with some K and some N last night, will post back tomorrow night if any other leaves start doing bad things by tomorrow (since the middle leaves are a bit light as you can see in the picture as well)