If I use 1/2 of 12ax7

[zorro]

Do I need to ground or do something to the unused pins of the other 1/2 of a 12ax7 I am using to drive a reverb tank with?

[Steve Conner]

You don't need to connect them at all. But driving a reverb tank is a hard job, especially with a 12AX7. If you connected the two tube sections in parallel, you would get more drive and/or longer tube life.

[zorro]

I stated it wrong. Your right. I am adding the reverb circuit from a princeton amp and trying to insert it into a delux 5E3 right after the 12Ay7 first stage in the preamp. The driver of the Princeton circuit is a 12At7 that is in parallel that drives the reverb. The output of the reverb goes to 1/2 a 12AX7. Thisgives me an unused half. But thinking about it, I might play with overdriving the second channel of the 5E3 with that unused half.
Thanks
George