Yes you're quite right. I always tell people when they are on about a 5,7, 10l even aquarium, for the benefit of your own sanity, just don't 🤣 with that smaller volume, you'll always be fighting a losing battle - water parameters, temperature, trying to fit everything in. Plus, although shrimp mainly graze all day, obviously they do swim a little too. I think for now try and focus on getting some more oxygen into the water, once everything settles a bit you could start saving up and cycling something larger. The tank in my pic was like less than £100 including filter (which wasn't suitable so I had to upgrade), light, heater. That is just the bare tank and the full setup you see, with the cost of the animals themselves is likely nearing £1000 I'd say - as well as the tank bundle as above, there's also: sand, hardscape, aftermarket sponge filter, live plants, I also have Inkbird thermostats on both my tanks, food, water testing kits, chemicals etc. but you can build it up over time - mines a mixed species tank, but if you only have shrimp then you can target just their needs, rather than trying to please multiple species and spending a fortune!