I have only been watering my seedling every 2:nd or 3:rd day. Had them in full sun ( up to 40C) about 8 hours per day. Humidity can be rather high at night. I let the plant mixture totally dry out between watering. Next spring I will replant them in pre-fertalised lava stone. I also have som coconut pieces to mix in with the lava stones.

Need to cut back drastically on watering and allow your plants to enter dormancy ..

While plants are entering dormancy - Be aware that the plants may loose all leaves (or keep them all) - either is okay and perfectly normal

Adeniums have only 2 seasons > wet - and - dry

wet = the active growing season (summer months in the northern hemisphere) water adeniums like a tropical
dry = the dormant season (winter months in the northern hemisphere) treat adeniums like a cacti

During Dormancy:
Do not use fertilizer -
Never allow the pot to sit in standing water -
Do Not over-water

Since you are entering winter ... water plants with one last soaking ... then choose a watering schedule you are comfortable with:
1) once every 3 months (90 days)
2) once every 60 to 75 days

Resist the urge to water !!

Over-watering during dormancy will kill adeniums

I think I`ll let my Adenium go to dormancy in a few weeks. I had some problems when the wind blow down the aquarium the where in. I had to repot them and I only had prefertalized lavastones. So I repotted them with the old soil and the lavastones. At the moment I can take them in at night to a place where the cats cant play with them.