yellowing on the edges of leaves?

This plant has some yellowing on the edges of the leaves. Any ideas of wgat t hth e issues coykd be? She's under 150w cfl right now. I'm starting her in a grow box and she will soon go outside. I have her in a compost blend with peat and also some shroom compost and poo... this seed was arandom free one, so we'll see how she does. Can anyone maybe guess what strain? I assume it's a pure indica because the leaves are so fat.

No one can guess what strain it is without a picture and even then it's dam near impossible. With respect to the yellowing it's normal as the plant ages. Believe me it's nothing to worry about. As I've said time and again it's the bud that your concerned with not the leaves.

of course I forgot to add the pic.

Make sure the PH of your water is always around 6. To me it looks like a slight PH problem. Adjust your water accordingly.

could be anything.

Strains are really hard to figure out until late harvest. Even then its guess work unless its something lemony like LSD or Lemon Sour Diesel. But if you have those two next to each other, could be really hard.

Anyways, could be PH.