1st post here I've just harvested today and when I took the plant out of the pot ther wer no roots on the outside of the plant with the result that the whole plant has yellow leaves with a poor harvest weight,I'm using bio all mix in 10 l pots an bio nutrients ph of 6.2-6.5 but being careful not to over feed also have intake and out fans with oscillating fan with indoor heater on all the time to keep temps up any idea what to try next to avoid this problem,many thanks in advance.