Thanks again, Amethystbelle! I went to Petco and PetsMart earlier and looked for Bactozym, Bio-Spira and Cycle. The only one I saw was Cycle. I took a sample of water from my new tank with me (had only been running for 25 hours since initial setup), and it tested in the safe range, so I decided not to buy the Cycle. Oh, I forgot to mention that I double-dosed on Stress Coat, in addition to the other things (adding water, gravel, live plants and some deco from my established tank and feeding "invisible" fish about 6 times).
I transferred Rusty over to his new tank about 6 hours ago (had to wait about 35 mins. for the gravel dust to clear up - added more new gravel & rinsed it thoroughly beforehand, but there's going to be residue regardless - I'd highly recommend the Eclipse hood/light/filtration system by Marineland to anyone - awesome). Rusty is adjusting quite well. It only took him 30 seconds to come out of hiding in the corner behind a live plant and start navigating his new environment. He's not use to a filtered tank, so he was swimming backwards a few times from the current. LOL! He seems very happy, and is EXTREMELY active ... swimming against the current just to prove his manliness.
He looks like he's having fun now, after learning how to "ride the wave" ... like a kid being pulled by a speed boat on an inner tube. However, I had to move a couple of plants around, cuz the current seemed to be taking him away in a few spots where he tried to rest at one point. I've had other fish before, but this is my first Betta, so I'm very impressed by this extremely quick upgrade and transition, compared to other fish. These guys are definitely very hardy, and I feel they do much better in a larger, filtered tank.
I hope this info. helps you, Christi. It's really amazing how much more active and lively Rusty is in his new 10 gal. tank. Please let us know when you decide to switch over to a larger tank. Oh, and, I didn't know if you were aware of this, but there's tank dividers that you can use to separate your Betta from other fish, if you decide to get more which aren't, or may not be compatible, with a Betta, as long as their water temperature requirements are within equal range. I've personally never used them, so I wouldn't know about any filtration blocks that might become an issue, but I know that VeggieGirl and some of the others use them, who can help you if you want to go that route.