I've got 10 day old plants that have a slight Nitrogen deficiency that I've had to start feeding. Yet, I see many people on here talk about not feeding their plants until they are a month or older above soil. Can anyone explain why some plants need fed earlier? I'm guessing it has to do with the medium? Thanks for any feedback.

any pics . whats up with them, why do they need food, at day 10?. if you want to feed . just feed at 1/4 strengh and then 1/2, to start with. just dont over feed. maybe even once a week at 1/4 or 1/2 strength

Heres a 10 day old with a nitrogen deficiency. I repotted her and fed her with 1/2 strength just once. I'll see how she recovers.

If it is nitrogen that is the problem you can also top dress a little dried blood in your soil. Do you have any pics?

how often do you water?

I don't know anyone the says wait four weeks before giving any nutrients. I know several, myself included, that say half strength at about two weeks and then bump it ud a quarter a week. BY the fourth week you will be at full strength. The exception would be if you used an enhanced potting soil that has nutrients in it already.
And I still say don't get your doctorate, if in doubt flush it out. VV

the main leafs look fine, if i was you id just carry on with what your doing. and what v.v said.

Thanks VV. As always, you're a big help.