New Clones what to do now!!!first grow!

Hi, So I just go my clones 13 of em , they are now sitting under 400watt hps at about 40cm from the light.
-Temperature is at 24 degrees celcius
-Humidity is arround 50 to 55
-They are about 1 inch tall
-Some of them have 1 to 4 leafes
-Ive been watering with botteled water
-I am currently growing in a big closet but I didint get any fans but I leave the closet a bit open so fresh air can circulate

When I go em they where in a very small pot and the roots where comming out. So I transplanted em in a bigger pot with neutral soil.

I put em on 24 hours light for 2 days , Just changed it to 18-6 today.

But now I have a small problem the end of leafes of all of the plant are turning brown WHATS GOING ON????

Could be anything nute related or fucked up PH. Ill let someone that does soil answer your question. Im a hydro guy.

For the soil I used neutral soil recommanded for clones , I got the clones from someone , I dont know what kinda soil he was using. I watered em myself for the fist 2 days with regular water then changed to bottle water.

ok ull need to find out wat the ph of the bottled water is cuz that culd b ur problem also wats the temp of the room are the lights 2 close it could be heat related r u using nutes if so wat kind, try raising the humidity to 65 70 for the first 2 weeks helps em grow and do u kno if the roots all took? um is ur soil just soil or does it have sand or perlite in it those could help cuz if its just soil u could have a root problem they may not be able to work there way thru the soil, try watering enuf to saturate the soil all the way to the bottom so the roots dont have to go searchin for water do u have holes for drainage ull need those um sorry so many ?s but theres lots of things that could b goin on Also try misting them with a spray bottle with a neutral ph of 6.8 - 7 Ill check bak with ya GOOD LUCK man