Hey, Betta Forumers!
I'm 13, and I've been thinking for a while about getting a fish. I've looked around, and Bettas seem to be a mix of easy and pretty, when it comes to fish care. I may not be able to get one, since my parents say I don't need one because I already have a pug dog, and I only need one pet

. However, should I be able to convince my parents that a fish is a good idea, and that I could take care of it, I have a few questions:
*I understand that unless you want a dead Betta, or many tiny ones, that you shouldn't put two Betta Fish together. However, I was wondering what the optimal size for a Betta bachelor pad (one fish tank,

) is. I've heard numbers anywhere between 5 and 20 gallons, and I think both of those are probably extremes. I was thinking 10, but I dunno how that is for sure.
*Who makes the best filters/heaters/tanks, and what temp. should their water be?
*What kinds of rocks/plantlife is good for a Betta tank? What size and shape should the floor rocks be?
*How often should you clean their tank, and how would you go about doing so? I understand you need to get all the ick out, without actually boiling it sterile, but what do you do with the fish while that's going on, and what are the tools required to do the cleaning?
*What do they eat, and how often do they eat it?
*What sort of extra things do you need to put in the water? I've heard of aquarium salt, but how much, and is there anything extra?
*The water in my area is pretty hard, is this okay?
*What is the safest area of a house to put the tank, and are there any other fish I should/could put with it?
That's all, thanks!