I just finished setting up a 5 gallon RCS tank over the past month. Six shrimp were added 3 days ago. The first 2 days they were very active. They constantly swam around the tank, up and down the sides, into the current, etc. Now I struggle to find where they are they are hidden so well. They move around slowly and mostly stay underneath my driftwood where I can't see them too well. I also have not seen them eat. I drop food in twice a day and it's partially eaten when I come back so I remove the leftovers. I read online that a healthy shrimp colony would swarm to food when it's dropped into the tank. Is it possible something is off about my tank? Or is the whole hiding / slow eating thing typical behavior?