thanks guys i was just curious as to how energy/life it uses up firing up a light. with the lights burning for 18months straight i would be afraid that if i turned them off they would burn out when i try to turn them on again. i use agrosun full spectrum flouros which cost between 17-20 dollars each at the local hydroshops so replacing 8 of them can get expensive. i will replace them before i start my grow again. only a couple more months till my probation is over!!!!!!!