When should I start fertilizer? Need tips

I have 3 Northern Lighting Automatic with 14 days of life. They are on the init state building the 3 and 4 true leaves on a 1L pot with:

40% perlite
40% peat
20% earthworm humus

I have the following fertilizers with me:

  • BioBizz Fish-Mix
  • BioBizz Bio-Heaven
  • BioBizz Root Juice
  • BioBizz Bio-Grown
  • BioBizz Bio-Bloom

My question is, when to start to fertilize? Should I wait until the decotyledons or the first leaves start getting yellow (nutrient deficience) and then start with fertilizers or should I start with them now and observe the reactions of the plant?

A post was merged into an existing topic: Can I have any problems putting water on the plant under the led or should I put the plant out, water and then put it on the led again?