One nice thing I know places with aquatic specialists, they are often allowed to add into to tanks like these fish (Comet) get over 12 inches long or these fish (Clown Loaches) can be 18", these fish like to be in groups of 6 or more, etc. Outlines of what size the fish really get next to the tiny 2" fish.
I am sure your new job will be a challenge for good and bad though, you have the opportunity to help people do things in a better way.
So learn all that you can so you can share pertinent information with your customers.
Especially if it is a store with SW
you have even more to learn about
I love GF! Nice pics.
Welcome to the community.
New to FW fish? First tank in a long time or EVER??? Need some info on keeping fish?
Start here - Aquarium Advice Article
FW Favorites right now Clown Loaches, any shrimp - SW Vase Red Mangroves