My first tank was an orb (30l), I now have a 180l tank. I actually re-set my bi-orb up last month to keep Endlers and Cherry Shrimp.
I personally cycled my orb in a fishless cycle, it was a long cycle, and lasted about 5-6 weeks.
Due to the nature of the orb, you will want to get yourself a good siphon/gravel cleaner to remove the build up of waste at the bottom of the tank, this should be done minimum of weekly as it will soon get on top of you.
It is easy to maintain, I personally do a 30% water change every week on my new setup, more if my water parameters say otherwise!
I kept a male betta in mine and he was perfectly happy.
THe ceramic media forms a big part of the orb's filtration system, just use a good gravel cleaner to remove any excess waste build up, no need to physically clean the media. If you feel the urge, you could probably do a handfull or 2 and clean in tank water, do not use tap water or you will kill the bacteria.
Regarding the service kits, if you do a search on e-bay or on the internet you will find a number of places that will sell replacement sponges that work perfectly well (£16 for 12 sponges) , you can then buy some activated carbon pellets and build your own cartridges. I only rinse my sponge out every week or so (in tank water) and it is fine. If you are worried about costs etc, you can cut the sponge in half and replace one half at a time.
I have removed the ceramic media from my orb and replaced it with large pea gravel (make sure you get rid of any small pieces as it will get stuck in the filter cavity), i also do not use the carbon or zeolite in my filter and have replaced it with some fluval bio max to increase the surface area for my bacteria. I have also changed the pump to a third party supplier which has increased the airflow.
Overall, i think it is a nice tank, however they do require a tight reign to ensure the water quality remains right for your fish, they are certainly aesthetically pleasing. Try and select fish with a low bio load as the filtration system cant really cope with heavy producers. The best advice i can give you is to take the instruction manual that was provided by ReefOne and throw it in the bin as the information provided in there is incorrect.
Any other questions, just ask,
Chris
