Why do some of my Acans do this

[alex.mccann99]

My Green and Purple Acans are huge, plump and ready to eat anytime. The red ones, don't get quite as big, but they eat. These others are just shriveled up all the time. They'll eat maybe once a week, but they never get big and plump. Should I move them to a less flow, lower light area?

 

[dbl]

Where they purchased from the vendor Acan Lord?

 

[instareefer]

I have moved stressed acans to lower light with good success