HELP (fast please) How do I fertilize seedlings

In the past i have always used Schultz Seed Starter mix but this year I decided to try not only using it with some seeds but start some in a plain (no fertilizer) mix. Also, I think I read from some others here that it was better to start tomatoes and peppers without fertilizers. NOW the seedlings with the fertilizer all look pretty good but the oneds without are much smaller and are yellowing. I assume I need to get them some food - fast - but don't want to shock or overfeed them. All i really have on hand is MG regular and Schultz regular fert crystals, and probably some triple phosphate. What do I give these guys to nourish them? Also, was it not such a good idea to start seeds without a fertilized mix - that seems to be a point of debate here.

I'd give them the Schultz or MG but dilute it to 1/4 strength (if they're still very small) or 1/2 strength if they're a little bigger. As far as starting seeds in a mix w/o fertilizer that is fine--the seed comes with a store of energy that lasts for a little while after it sprouts (that's what those first seed leaves are for). I usually start fertilizing when they get their 2nd set of true leaves. If you use a seed starting mix that has some fertilizer in it, all that happens is you buy yourself a little more time before you would need to start fertilizing.

I use diluted fish emulsion, watering from the bottom.