from one site

fish emulsion is good stuff. Make sure your plants are ready for nutes first - three weeks doesn't necessarily indicate it's time to fert. Wait for the cotyledons to yellow and start to fall off, then apply fert (this is a sign that the plant has used up all of its own nutrients) Start off by using it at 1/4 strength and gradually build up the concentration, but never exceed the recommended strength on the bottle. So, grab a gallon of good water and only put in 1/4 the amount of fish emulsion recommended on the bottle to start. Feed like any other watering and you should be well on your way.
Yes, 5-1-1 fish guts is good shiz fer the vegetative stage of growth. Start off with 1 tablespoon per gallon of water and water 'till it pours out the bottom of pot. You can use up to 2 tbls/gal. later on. Watch how much yer babies like it. Give 'em a dose every other watering, they will love it!
hope it helps you