Aquariums: First planted tank!

My first planted tank i started back in june. 20 gallons with 6 neon tetras, 4 harlequin rasboras, 6 kuhli loaches some ghost shrimp(idk how many any more, around 8 ig) and two nerite snails. i would like to add a betta fish if it’s not too over stocked but im not sure?? parameters have been stable and haven’t done a water change in 3 weeks only water top offs and fish seem to be doing well, just don’t know if it’s too much to add a betta fish, let me know. but really proud of my plant growth for it being my first planted tank just wanted to show it off!