@sollat Nice ones-- that Euphorbia looks great 😊 I would look up the growing cycle for each of these if you haven't already. That Opuntia is clearly making some growth-- *most* cacti are winter dormant at which time you should water little if at all (depending also on temps). Often flowering (unlikely for Opuntias indoors, but maybe the Mammillaria) is dependent on a winter rest. Succulents like the Euph are all over the map with growing cycles, you have to research each.
@sollat These are all high light intensity plants so just watch for any hint of etiolation. My rule of thumb would be if there is natural light they should all be as close as possible (if it were only natural light in winter, you wouldn't water much), and depending on the kind of artificial light, they might need to be with a handful of cm from it. So far looking good :)
Schönen Abend und gute Nacht später 
