defeciency

Hi guys, I have a problem with one of my girls at the mo. Problem started 2 weeks Ago. I'm not what you would call a noob, however have been really lucky when it has come to problems/ deficiencies. So have limited experience correcting issues. I basically have yellowing of some leaves. Mainly...

I have a problem popping up. These plants are defecient in something. I think its both from what iv researched and experienced. These seedlings were in roots organics before transplanting to coco with canna. I got all the dirt off before transplant. Iv done this before never had a problem.. I...