I just got back from my LFS and told them I wanted to upgrade my single strip light to a dual strip light. I had one 40 watt Power Glo bulb and now have two but they are not Power Glo. I am sorry that I can't remember the name of the bulbs but they told me and showed me that these are the bulbs they use on there planted tanks. My question is after replacing the hood the light output seems less then it did with the one Power Glo. Does this sound right?