Thank you for the replies. The nitrites are 0.25 probably because of too many WC's to fast. Nitrates are just not there yet it seems.
As far as ferts for plants, I "think" that a little goes a loooong way here. In our efforts to follow the "book" and do things really correct, do also think we are shooting ourselves in the foot at times. The flair-up of diatoms just might be a normal thing and part of the overall cycling process. The flair-ups just might even be somewhat random and only affect tanks were there is a "perfect storm" of conditions.
The one thing I "think" I'm certain that started the diatoms were disturbing the substrate too much with adding and removing plants and just stirring up the gravel. There was extra ditritus flying all around the tank then. Couple that with a dirty filter and low circulation, and then,... that could have been too much for the bacteria to deal with. I'm starting to think that when diatoms appear, they are sort of like a "third" good bacteria invading the tank, only they're not so good. Then the tank settles down again after a bit of house cleaning. Time will tell.