What's the difference? From my readings and basic understanding of light bulbs the HO should be better, but it's half the price. Am I missing something or has PetCo gone a bit wobbly? The T5 is $50 with the T5 HO is $25. I'd rather get the HO because a) it's cheaper and b) it'd fit in the viv better, but I don't want to slack off and relies that it's actually worse then the regular T5.