When should I add liquid fertilizer?

[Michigan.Out.Of.Doors]

I will be popping in a week or 2 and I'll be using a 50/50 mix of Fox farm ocean forest and pro mix hp,after 1-2 months I will transplant outside when it gets warm enough,roughly what time should I add liquid fertilizer?when will the soil most likely run out of nutes based on your expiriences

 

[TripsRabbit]

2 or 3 weeks, when the cotyledons start to die off.

 

[Michigan.Out.Of.Doors]

2 or 3 weeks, when the cotyledons start to die off.

I've got cal mag,bio grow and fox farm grow big,tiger bloom and big bloom

 

[Sparky1980]

I have a few that are about 5-6 weeks old and have been outside in pots since germination. I just today fed them liquid nutes for the first time, as the cotyledons are almost completely gone. Best of luck!