They're perfect for bettas

You should only keep plants in them

A tablespoon of regular dirt underneath a gravel bed, underneath sand is the best soil medium, add a couple steel nails too.

Add plants, and then don't add fish indiscriminately.
Get dwarf crayfish instead. also if you can bury your airstone in the sand, like inside a sponge, underneath a big rock, you'll get better plant health. Those things have bad airflow and waterflow and you can make something just as pretty with a huge jar and a bright led bulb lamp in your room.

>>2160511
Your light should be on a timer.
Or you get algae.
It'll be a mess to clean, but if you wait to add fish, once the plants are established, you can look into diy co2.

Anubias is a plant that grows fast when in bubbles 24-7.

>>2160512
cryptocorne is another good specimin.
Amazon sword (as shown in op) gets too big and acts finicky once it is stunted.

But cryptocoryne wendetti especially the red variety, is great in dirt tanks, if it's a fuckhuge plant, expect most of the leaves to die, but it comes back, especiallly if it's planted near bubbles, and it can find dirt.

>>2160465
Here. Everything you need to know.

http://www.bookmasters.com/marktplc/00388Shrimp.pdf

>>2160512
Any suggestions as to the number of hours of light it should get per day?

>>2160682
6-12. You'll have to work out what works best for the plants you have without causing algae blooms.