What filter are you using on this tank? I have an identical size one. Any problems with shrimp jumping out at all?
It is a Red Sea Nano filter. Azoo also makes one, which is identical. I attach window screening to the inflow so the shrimp don't get sucked into it. It doesn't affect the flow much and haven't had issues of clogging like sponges can.
No problems with jumping shrimp. In my experience, RCS are not fans of doing suicide jumps out of the tank, even in my Mini M.
Scraped some of the brown algae specks off the glass and added DIY CO2. I jammed the CO2 tube (has a chopstick piece on the end) into the tree stump to help keep the CO2 in the tank as long as possible. I may purchase a Hagen Elite in the future to use as a filter and diffuser. It does a great job filtering and diffusing in my 7.5G cube.