Tanks and feeding questions

Question
Hi!
I was wondering if you could help me? Yesterday, someone at petsmart told us that we should feed our fish once every 2-3 days but we have been feeding them twice daily since we got started with aquariums about a year ago.  We have a freshwater aquarium with an Angelfish, a Plecotomus, a long-finned Black Skirt Tetra, and a Gold Skirt Tetra. Have we been doing this all wrong all this time?
My second question is that I have a thermometer that sticks onto the inside of the aquarium, but it won't stay on. How can I fix this?
My third question is- we just bought a 30 gal. tank and put water in it yesterday.  How long do we have to wait until we can add fish to it? We have been told a week, but this was from the same girl who told us to feed them so much less, so we just want to verify that is correct.

Thanks! (and thanks for volunteering here, it really helps to have people who are willing to be around for us in need!)

Tory

Answer
Hi Tory, number one rule! Don't ever listen to pet store employees! That is why they made this site lol... You were doing fine with the twice daily but to get them back on track feed them once daily for 2 days then start feeding them twice daily again. I've fed all my fish twice daily and they love it and are very healthy! Truthfully you don't have to have your thermometer sticking on the side, just stick it in the water and check it once a day or so and that will work out great. Again don't listen to pet store people! You should wait about 2 days to put fish in there to be safe. If you add a product called Cycle it will speed everything up and you can add them in about a day. But 2 days to be safe. And your very welcome for your answer I love doing this and it gives me a break from being around sports and high school all day. Thanks for coming to me to ask questions and thanks for letting me know you appreciate it! Please let me know if you have any more! Good Luck!