Merry christmas guys. My girls are 5 weeks old now. Ive used HPS 600watt 18/6 cycle. Temp is around 20 degrees celsius and Humidity is around 40~50%. Although there is a grow room and I'm using tent but It is winter and hard to warm temp up. and soil is just normal one but I left soil in pot for few months outside. Leave have turned to yellow since from 2nd week and I guessed happend by low nutrition so I gave little amount of nutrion to them for 2 times for 3 weeks so far(water every once a week). because I've heard that too much nutrition is harmful for young plants. as you can see in pictures, their leaf tips are yellow and bottom leave are 100% yellow What is the problem? should I give more nutrition or do something else? I need a guidance. HELP!!
Try Cal-mag, looks like deficiency, there are brands to choose from also, just use like the label says, it worked for me