Hello! 
I've been searching more into fish recently, and I had a few questions.
- 20 gal stocking ideas? Any of the peaceful nano fish are fine to pair with a betta. This would be neon, cardinal, black neon, ember tetras; chili, harlequin, lamb chop rasboras; livebearers; etc. My favorite pairing with a betta, and the easiest, is a school of corys. Keep in mind that panda corys do not like temperatures above 76F (24-25C), but this is fine to keep a betta at contrary to popular belief that your betta will suddenly die if it is not kept at EXACTLY 78F. Snails and shrimp also make good betta companions, though I do not recommend cherry shrimp as they will too easily be a snack for your betta. Ghost shrimp tend to be incredibly cheap, so they would be a good experimental tank mate. I also do not recommend sorority tanks (multiple females) for beginners, and I do not recommend divided male tanks. If the males can still see each other, or if you use a mesh or sponge divider in which they can smell one another, it will still stress them. Having a divided tank that is male and female can cause the female to start a breeding cycle and become egg bound if she does not breed. Or, it again can cause stress because the male will obsess over her. Divided female betta tanks can work okay.
- is it okay if I use plastic plants with bettas if i've melted the sharper parts with a lighter or sand them down? This is more effort than it's worth. I know silk is better than plastic, but unless your decorations are like stupid sharp, you should be okay.
- how densely planted (with fake plants) should a betta tank be? As densely as you think is pretty. Their natural habitats in south Asia are heavily, heavily planted. Especially if you get a long-tailed betta (so anything that is not a plakat), it will not be a fast swimmer.
- i've heard it's okay to use lego to DIY things for a tank. would it be okay with a betta? Not recommended.
- i've heard shells aren't recommend in freshwater tanks due to calcium contents or something along those lines. i've a shell hideout that's supposedly made for freshwater tanks, should it be okay? I've never heard of this. Calcium is a mineral that is in the General Hardness mix, but unless you have a very low pH, your water should not be eating away at a shell so much that it is drastically affecting your GH. Edit: If it makes you feel better, it's common for people to put cuttlebone in their fish tanks if they keep snails or shrimp so they can eat on it and get a calcium supplement. So, shells are very likely fine.
- ethical places to get a fish? What is likely more important about being ethical is not where you bought it from, but what fish you bought. Many species of fish are still wild caught for the trade since they just don't readily breed enough in captivity to keep up with demand. We don't know exactly how these fish are being captured or if their numbers in the wild are being monitored. So if that concerns you, research any species you are interested in to see if it is most commonly bred in captivity or wild caught.
Thanks in advance!
