The endcaps will be different. Teh VHO
bulbs on my tanks are larger in diamater than the NO
florecent bulbs in my celing fixture at work. The diamater of florecent tubes is usually marked on the tube itself by a T-## scale. VHO
bulbs are almost allways T-12 and most normal florecent bulbs are T-8. The smaller the # the smaller the diamater of the tube.