Leave Tubes In Standby Mode or Not?

Hello everyone, I have a question that I hope can be addressed by some of you with tube equipment. Are you REALLY supposed to leave your tube equipment "on" or in "standby" when not using it? What if it has a "soft start" like a SF Line 2 preamp? Does it actually help or hurt in terms of tube life to softstart on/off or leave in low power standby. I have a Sonic Frontiers Line 2 preamp, and in standby mode the tubes glow, so I just can't help it, I feel guilty by leaving it on....I feel as though I am wearing out the tubes. Am I? My present thinking is that I would rather turn it on every 2 or 3 days (other days I listen to my other system) for say 6 hours and I don't feel badly about turn-on effects to the tubes because of the soft-start feature. I let it warm up for at least 1 hour before listening. Hmmm. . I suppose some will say leave it on all the time, but how long can tubes last that way? I am new to tubes if you cannot tell. Thanks! (note: my guilt was newly trigged by the related CA Power thread, which I am also reading, but this is a narrower issue).