My lighting is not working today. I have 4 VHO tubes on an ARO ballast. They are all 4 wired to come on and off at the same time. So, can I assume that one of the bulbs is burned out and that's why it is not on? The bulbs are less than a year, so they should not have burned out. But they probably need to be changed anyway. With a holiday weekend, what if the new bulbs don't arrive until Monday - will the corals be ok that long? There's not much in there and most is small: a frogspawn, xenia, zoos, ricordia and some mushrooms. Thanks, Beth.