Tbbyy

hey,.....so looked at album and im sure others have answered this already but you are using some form of a metal halide/mercury halide bulb that emits a blue spectrum(GREAT FOR VEGETATION) However, if you dont have any ventilation or any wind and fresh air blowin through there then your gonna have some serious heat stress going on to the plants and that is the reason they havent grown any cause they are way too hot and they are doing their best to conserve water in their cells and veins so they shrivel up like that + the fact that the heat is also cooking the edges.
Also put your hand just above the tips of your tallest plant for a minute, and if it is getting hot then it is way to hot for your plants, also a digital thermometer placed at exactly the height of your tallest plant will let you have a more accurate measurement of the temps of that altitude LOL haha altitude..........

Anyways..........everything else looks great though and keep it up!

Enjoy your grow

Your power consumption wont be high. The light looks like a 250W or a 400W.
Look @ it this way. You know the cheapo heaters u get from Woolies? They chew 2000W per hour. Thats 5 times the power of ur light.. Some people have 2 or 3 kids who each have a heater and leave em running all night. Most bills in Winter are huge anyway.

The light is a Metal Halide.. Or it's predeccesor the Mercury Halide. It has light in the Blue Spectrum, so it is ideal for Vegging your plants.
As for the burn on the leaf try using using something like this to help you - Marijuana Plant Abuse

Hey dude i looked throught ur album, but couldnt see the type of light. Get a photo of it either right before it comes on or right after it goes off so as to not disturb ur plants too much.
From ur description though if it contains mercury it should be alright, a little off, but the plants will cope.

Hey dude, that list could be virtually endless.. Fluros, CFLs & HIDs are all acceptable to use, but will give varied results. Stay away from Incandescants and Halogens though..
Y dont u tell me what light u wish to use & i'll tell ya whether or not it would be alright?