need help with food

I started some seedlings a couple of weeks ago ,,ther yellowing real bad..Im growing in rockwool like I always have ..Ive set up hydro setups in the past with much success.The only difference is my buddy is a big time grower and he would ussually drop me of a couple of gallons of that special food allready mixed up in a formulla..Now Im having big problems ,,I have about 8 plants going ,,,I do have a ph tester,,,its between 5.5-6.0..I am running a 250 watt hps ....I guess im having a big problem with the food ,I have no idea what to use ,i grabbed some bullshit from home depot,,I dont think its working,,,,and for some reason my rockwool hase some green mold on it ,,,,,any help would be greatly appreciated!!!!!!!!

I just checked ,the food Im using is Vigoro ,,On the back it says 24-8-16 with nitroform....Is this good or no???

thats waaaay to high!!! u want somthing like 10-4-4 or 6-4-4...

one on the left is to flower..but the fox farm on the right is for veg. i guess a lot of people use fox farm..it works great for me! good luck man...

Thanx alot man I knew somthing was terribly wrong!!!!!!!!

no prob. man... u shouldn't feed ur plants untill there atleast 4 weeks old (1 month)..
good luck!