No, 5 more kuhli loaches won't be too much for a 55g. They stay very small and you aren't near being overstocked yet. I have 7 in my 38. Just make sure they have hiding places. Mine love to hide in the base of my hollow castle during the day and come out and get real active at night.
You'll probably be best forgetting about the crayfish unless you get a specific tank for it. Your pleco and loaches would also be at risk, sharing the same strata as the crayfish. Anything that it can reach will be at risk.
I like my ramshorn and mystery snails and have a variety of colors in my different tanks. But for anyone not wanting to propagate them, I suggest nerites as nerites require brackish water to reproduce. They don't do it in freshwater.
Wood shrimp, cherry shrimp, Amano shrimp and ghost shrimp are all in my tanks. They're all lots of fun to watch, especially when they "fly" around the tank.
Use caution when putting any with the betta though, both of mine eat shrimp.
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Tina
Puffers:
Auriglobus silus x2
Colomesus asellus x1
Tetraodon travancoricus x1
Tetraodon biocellatus x2
Tetraodon nigroviridis x1
Tetraodon baileyi x2
Tetraodon lineatus x1
Tetraodon palembangensis x1
The greatness of a nation and its moral progress can be judged by the way in which its animals are treated. - Mohandas Gandhi
