Ok no smart answers. I have to replace all my bulbs. They are all old (over 1 yr old). I have 2X165 VHO's and 3 X175 MH on a 200 gallon tank. I was just going to change 1 light bulb a week starting with the VHO's and work to the MH, but this would take 5 weeks. Can I just do 1 every 3 days?