auto purple opium

All 6 popped but 2 failed to grow a tap root properly and withered, but the other 4 look good, 3 got slightly leggy while 1 has stayed very short, just a few millimetres above the surface. Once popped I put them into a plagron light mix with about 20 percent plagron mega work mixed in, watered well and now I just check to see if they're dry and water when necessary. The light is set to 25%, Tent temp is 26.4°c steady through the day and humidity is in the low to mid 50s, I'd like it to be higher but I don't have a humidifier.