fluorescent tubes

New fitting are about twice the maximum cost of second hand unit. Only one double fitting can grow many plants until they about 2 weeks old. As they grow taller the light is too dim at the sides and bottom of plant, more tubes will be needed to light these parts of the plant. The light from fluoro's needs to be very close to the foliage about 10cm. max., heat may cause burning or curling of the leaves if there touching the tube. If there are 6 large plants they will need 10 or 12 of 36 watt fluorescent tubes for my cannabis seeds.

cannabis on rockwool

The pH of the nutrient solution should be checked regularly with a pH meter. pH too high: lower it with Nitric acid (during the growth period) Phosphoric acid (during the flowering period) pH too low: increase it with an alkaline solution (during the whole period) Take care with these acids because they are corrosive for your big bud feminized. The pH of a nutrient solution for growing your "favourite plant" should be between 5 and 7. Because rockwool is made from rock and rocks can be very alkaline, rockwool can also be very alkaline itself. This results in an immediate rise of the pH value of the nutrient solution as soon as it comes in contact with the rockwool.