need help no buds

Hey
just need a few quick answers. im running a 2 plant cabinet system with 400watt hps light. this is my second grow the first grow went well buds were massive. this time round the plants just seem to keep flowering its not budding up like last time. their on week 6 and im pretty sure last time were well and truly budding up. ph i keep just below 6.0. im running the lights on 12/12 i noticed at night the temp drop alot could this be a cause? also someone told me i should be running a heater in the water if not it can shock the plants? anyone got any tips? ill try organise pics soon

i imagine you are using clones, are they from a different mother than the last time? i have found that after the first set of clones from the mother, they get weaker and weaker each time. after the first go around. what i have experienced, the yield was cut in half from the first time

Hey
thanks for the reply..i tried to clone but its harder than i thought so i used seeds which were from the same plant. so im not thinking its genetics of the plant..
cheers sidy