5-gallons is quite small, so there's not a lot of options, but I recommend snails or shrimp. When it comes to shrimp, bettas can be shrimp eaters but it really depends on the fish, so purchase 1 or 2 neocaradinas as a trial.

 

Since corys feed off of algae and extra food at the bottom of the tank, I think a 5 gallon wouldn't suply enough algae for them since you'd have to get 6 minimum. I would reccomend some shrimp for a 5gal but be ware the betta might eat them, hit or miss.

To introduce your betta to tank mates I'd reccomend taking her out of the tank, rearranging a few things in the tank, adding the shrimp or fish (if you decide to get a bigger tank), and then putting the betta back in. This will make her think it's a new terrirory so she won't be aggresive.

Also sidenote, can we get a moemnt of appretiation for your tank?! It's so pretty! Great job on that

 

You might be able to get away with a few small fish, but that might be a struggle. It depends on your betta with the shrimp, as betta fish and have different personalities, each with its own aggressiveness! Keo, sadly passed but he was extremely aggressive. He dident flare at me, and seemed to adore me! But sadly, when I tried tank mates, it ended up terribly. Jaina, my current female, Is extremely relaxed. I have put neon tetras in her tank before, and they did just fine! (But the neon tetras sadly didn't make it. Not because of jaina, or a lack of trying.) Anyways, it really depends on your fish!

@TheBettaKeeper our profile picks look similar!

 

Haha, you're right!

 

I'd go with small snails. They keep the tank from not getting overwhelmed with algae and my female betta Bubblegum lets them be for the most part. If you move to a ten gallon tank, you can throw a few platys in. My tanks been running like this for more than a month now and everyone is doing great.

 

Your tank is gorgeous, I'm in love with this setup.