Need Lightbulb Help

Replacing light bulbs in next couple of weeks. My current flourescent is a Coralife F40 T12 BP whatever that means. The light I want to replace it with would be 6500k. What I am finding on Dr Foster and Smith is Zoo Med Ultra Sun Trichromatic Fluorescent Bulbs. The are 48 inches, 6500k, but are T8. Will they fit in the fixture? If I am correct the T12 represents the diameter. So I know the length is good. I just am not sure if the T12/T8 issue will be a problem.

My other fixture is Coralife 48 Inch Aqualight With 2-65 Watt 50/50 Lamp Straight Pin Base. It came with a 50/50 one of them being a blue antic. The guy that sold it to me sold it for about 50% of retail straight out the box. Convinced me to try the blue antic in freshwater. Can't say it had a distinct advantage but my plants grow and when I turn off the flourescant it looks good. My question is, is there an interchangable bulb if I do not go with the blue antic again?
http://www.marinedep...&tab=5&size=48"

Thanks in advance.

The T12, T10, and T8's are all interchangeable. Supposedly your T12 bulb is less efficient compared to the T8 - basically that's the only difference apart from size. Those T12's are MASSIVE...have fun squeezing your fingers in there

I personally don't care for the 50/50's. I've purchased replacement dual daylight compacts on ebay with decent results.

I did a little experiment with lighting when I setup my 75gal

see my post HERE for results