yellow tips on new growth?

hi just wondering if anyone can help me identify what this is? soil grow with biobizz all mix around 4- 5 weeks veg, adding around 4 ml of biobloom nutes with each watering (4ml :2l ratio) other plant is recieving the exact same treatment and is flourishing with no problems??? using cfls.

Lighten up the food on the plant having issues. You have a little nutrient burn. Over fertilized plants will start on the tips of the water leaves and work there way in. Feed the burnt one water for a week or two.

The new growth tips are whats concerning here. jaybray is correct. Lighten up the feeding a tick and continue on.
The tips of leaves (other then new growth) can have some yellow to brown on them (about 1/16 to 1/8 inch in). That indicates that you are pushing them at about the plants limit for added fertilization.
The yellowing of the new growth tips is an indication of over feeding! Be sure your pH is ok too (although I'm inclined to say that's not part of your problem. It can contribute here).

i thought new growth yellowing was a boron defficiency but i guess it could be too mucxh nutes

Micro nutrient def is VERY rare in soil grows.....Same for hydro if you use the complete line of your pref nutrient and keep your pH in zone.
The only time I have ever seen one is when I left out the rock dust (oopsy) from making a supersoil type soil some years ago. Rock Dust adds the micro metals and some other things in soil making.

ok thanks for help people, is a flush in order here?

ph is usually around 7

No flush. Just lighten up the feeding.

I push my feedings intentionally until I see yellow tips. That means you're giving them all they can handle. Once I see yellow tips I back off the feeding just a tiny bit.

Sent from Northern Colorado.