[Micho]

Hey there, welcome to the forums.

1) In my opinion, anything above 2.5g makes a good home for a Betta, but bigger is always better, and at times cheaper too. My 10g set was way cheaper than my 2g, kinda sad. ):

2) Having a 10g tank and above opens the door the a community tank with a Betta. In a 10g you could have one schooling species I would recommend; Ember Tetras, Pygmy Cories (you'll need sand substrate), Endlers Livebearers, Guppies, some species of small rasboras, and so on and so forth. Snails and shrimps also make great tankmates. But before choosing a tankmate you'll have to find out your water's hardness and pH, different species of fish live in different water parameters, so I suggest you do some research on that.

3) Bristlenose Plecos get quite large, length wise they need a 2.5 foot tank. Which a 10g cannot provide.

I would suggest buying your Betta's tankmates first and quarantine them in the tank itself, after one or two weeks of quarantine some may have died off, if so replace the ones that have died off and quarantine again, maintaining a shoal is very important in a community tank, or else fish will get nippy and aggressive.

4) Up to you, live plants are beneficial aquariums as they suck up ammonia, nitrItes and nitrAtes which are harmful to fish in excessive amounts. But they require the correct lighting and fertilizers in order to thrive. Fake plants I wouldn't go with the pet store's plastic plants, they're expensive and often rip delicate Betta fins, instead search around in the dollar store for silk plants, they're soft and cheap. Just soak them in hot water overnight to leech out any extra dyes.

5) Bettas are freshwatrer fish, don't add salt.

6) Bettas can tolerate a wide range of pH and hardness, you'll just have to worry about your tankmates if you're having any.

7) There's a lot of those "kits", just look around. They're really cheap and inexpensive, my 10g was a kit. Tank came with a hood, lights, and filter, it was like $40 I believe, way cheaper. But I did switch out a lot of things, I bought a better filter, and I changed the bulbs from incandescent to fluorescent 6500k bulbs for my plants.

Hope that helps.

 

[Micho]

I would say to the Otos. Mainly because Otos are algae eaters and they rip through algae really fast, they need to be in a stable, cycled tank that's heavily planted.

You could do Cories though! Please remember that in order to house Cories you'll need a sand substrate, not gravel. You could house 8 Pygmy Cories easily. I wouldn't do an undergravel filter, and yes you will need a filter. In order to cycle the tank you'll need a filter and also filters are just needed if you want tankmates. I recommend the AquaClear 20 filter, even though it's recommended for 20g tanks. If you can't find Pygmy Cories, maybe Bronze, Sterbai, or Julii Cories could work too. 5 of them or so.

 

[Micho]

Nothing wrong with starting off with just a Betta. That's what I did, started off with those lousy Betta tanks which doesn't even hold a gallon, upgraded immediately to a 2 gallon, with a heater and all that jazz. Later down the road got a 10 gallon tank set for a cheap price, then upgraded my Betta to a 2.5g for more swimming room.

I'm sure there are those 5 gallon tank kits out there. Just look for them, brands like Tetra and Top Fin make them extra cheap, I know Marina is pretty expensive as well along with other brand names. Try looking online as well, secondhand tanks are way cheaper and all you gotta do is give them a good cleaning and it'll be brand new.

And yes, where Bettas come from they live in shallow rice paddies with little to no oxygen in the water, so they have a labyrinth organ, which allows them to breathe surface air. They won't need those bubblers like Goldfish do.