Thanks for your great work Hataman, Iā??m going nowhere with thisā?¦ Your ideas seem right, and symptoms are just what I have.. When it first happened I did think I had a pH problem causing Iron deficiency, but by the time I sorted it the damage was done and they never recovered.

Since I have been extra careful with pH & feeding, and the plants look really great until they get under the flower lights. Then they seem to have a strong burst of growth in the first week and the top leaves start to yellow by 10 days. Iā??m now trying both flower & veg lights together, and only feeding pH adjusted seaweed.

The latest plant has been under flower for 10 days now and after reading your post I have just given it a shot of Iron (Sequestrene), it shouldnā??t do any damageā?¦ Iā??ll let you know..