well my guess is if you have no way to check your ph...it is probably off a little, and whatever deficiencies you are seeing is caused because they are locked out... I can't tell anything from your pics, the whole thing looks yellow to me. Don't waste your money on the strips, spend 30 -40 bucks and get a good tester, if you are going to conyinue to grow, after this one is done, the ph meter will be your best investment. If your ph is off one way or the other, it will lock out the nutrients and your roots will not be able to uptake them. So if it is N deficient, it doesn't neccessarily mean that there is no N in the soil, just that the plant is not able to take it in.