V shaped set of leaves

Hi everyone, it would be great to get some feedback on my question thanks. I have just planted 6 seeds that i got out of some weed i bought. I germinated them and two only appeared cracked with a stem protruding out. this was only after two days. the two that cracked are now growing and the other four have showed no enthusiasm to grow yet. whether they will, i dont mind!
On the first set of spiked leaves that come out (the one spiked leaf pair), they seem to be in a V shape. i.e: the central vein of the leaf is shadowed by the sides of the leaf which seem to be 'closing in' together. It does not seem too extreme a problem as i think it might be because it is growing so fast, and developing more surface area to catch the lights rays before it flatens back out. both leaves are growing facing predomenantly towards the light and pointing the leaves upward which is a good sign to fast growth i hope i am right in saying this, but if i am not. please anyone, help me out! thanks

This Is A Goos Sign, What Lites Are You Using?.

i am using a 400watt hps.
I used it last year for budding, do you think i need to change the bulb??
Also, i am thinking of making a growroom inside my outdoor plastic greenhouse which is very light and easy to dismantle. would this be a better idea than the closet im using that gets very cold at night. for this reason i only give them 2 hours dark each night, and i think the plastic greenhouse would be warmer.