How many cory catfish in a 10 gallon tank with a betta

I've heard some good things about Cory cats and bettas. I have a male betta fish and if I get him a 10 gallon, how many corydoras could comfortably fit in the tank?

Would I need a filter? Because I don't think I'll get a filter. And if I don't have a filter, the tank wont "cycle" but the fish will be fine if put in "immediately" (when the water has settled, heater is ready, plants and/or decor is in....)?

I was thinking 4-6 Corys in a 10 gal, but I probably wont get him a 10 gal, this is just ideas being pitched around. If I did this how often would I need water changes?

If you want to get cory cats in a 10 gallon, make sure they are the small kind like pygmy cories. Larger cories like albinos need about 20 gallons of space. If you get a small cory for the 10 gallon, I should get about 4 or 5 so you don't overstock. You could get 6, but it would be riskier.
You NEED a filter if you're going to get cories. They produce a good amount of ammonia so it would be very hard to keep the levels low enough without a filter. Filters are not that expensive, but they will save you tons of work and make your fish happier. If you have a filter, 25% water changes every week and a 50% once a month would probably be fine. I'm not sure how often you'd have to change the water without a filter, but it would be done a lot more frequently.
Cories make great companions for bettas, so if you have the right setup, I would recommend you get some. My betta likes to sift around for food next to his cories which is really cute.

Alright, I'll keep looking around. Thanks for the info!

I think its a great idea! I have my betta in a 30g with so far, only 2 cory cats, and he loves them! Plus, they are adorable to watch! But be mindful that cory catfish like being in bigger groups, at least 3.

I've had my pygmy cories in with my betta in a 10 gallon for 9 days now, and they really go great together. My betta was checking them out in the bag while getting them adjusted, and chased one for a few seconds went they first entered the tank. He quickly learned that they are way to fast for him, and ignores them for the most part now.

I got a small school of 6 and they have plenty of space/filtration. They are excellent cleaners, very social and playful. I highly recommend them, but make sure you have some soft substrate like sand/smooth gravel/soil. I would also recommend a filter, and letting the tank cycle before adding stock. Without a filter and/or alot of live plants, you're going to be doing a LOT of water changes.