Hole on seedling's leaf

Hello all

I got a seedling amongst others that is 2 weeks old and has been doing great so far. Only set backs have been a slight yellow on bigger leafs (possible nitrogen def, gave it biobizz grow yesterday, did i do right?) and a slight drooping of bigger leafs which i think indicates it needs a transplant (i got it in 0,8l pot). The strain is unknown. Anyways today after i got back from work i noticed it had a small hole on one of the 2 bigger leafs. It looks as if it has been burned by a small cigar. Unfortunately i dont got the luxury of a photo yet, but will be able to post one soon.


Please guys, any fast help would be appreciated a lot. I'm afraid of pests problems and if this could be one, right? i'd like to fix it now that it is at its beginning. Any ideas what it could be?

temp=26 celsius @ lights on, 20 @ lights off
RH has been 40-60% these 2 weeks of its life, except today that it dropped to 20%
Distance from light was 5cm from the initial 26watt blue cfl, and now is 30 cm from cooltubed 400 watt HPS (3 days now)
I gave it rootjuice and bioheaven first 10 days and yesterday i gave it some more but with some biogrow in it too (been giving the nutes with 200ml water every 3-4 days)

Any1?

oh and i forgot to mention something that might be important. I did a mistake yesterday, i first watered-feed the plant and then i remembered to test ph from water that came from the bottom, it came out 8+ .......
I dont know f it is capable of making holes on leafs, but i got to mention it

Hello guys, i finally got pics for my 'holes on leaves' problem. Pic 1 is from 5-6 days ago, and pic 2+3 (not very clear, but the black spot on the edge is a hole) are from a hole that happened today. I searched for bugs as best as i could but i found nothing? WTF is going on? the hole from pics 3+4 happenes this morning in 1 hour, i checkd it and it as ok, then 1 hour l8r this hole was there. Tha plant is 2 1/2 weeks old. Temps are 20-22 celsius @ night and 25-28 celsius @ day. I've given it rootjuice and bioheaven + very little biogrow a few days ago.

Please guys help. I need to tackle this prob now that it's at its beginning.

bump, im curious as to what this could be