ahood
Member
I have a T5 22" HO fixture with Arcadia D3 HO 6% HO bulb. The package says to jange every 2 years, but I thought you were supposed to change it every year. When I ordered it a year ago, it came with an extra bulb. (The fixture only holds one bulb) Is this bulb still good to use since it has not been opened or anything? And should I go ahead and change it?