First of,what kinda soil you using?Also,if youre not planning in flowering anytime soon,go to Home Depot...and buy a bag of BloodMeal & BoneMeal.Theyr usually made by Vigoro.Now when you get home,get a gallon(empty a gallon on milk,etc) of clean water and put a tablespoon of BloodMeal...Now use this water as your veg nutrients!Trust me its good shit for vegging plants,its 12-0-0!!!Now is that alot of nitrogen or what!?Then repeat this but use BoneMeal for flowering...
Remember that BloodmEAL IS FOR VEGGING..and bonemeal is for flowering.You can alos use urine for vegging plants,but only if your diet is clean.I dont recommend it,but they say urine is a very good fertilizer(diluted ofcourse)....
Oh I forgot,spent coffee gorunds is a very good source of nitrogen for vegging plants..just add to soil,or mix with water.Use these homemade fertilizers and your plants will EXPLODE with growth.Any questions jsut holla at me.