Planted Tank Guru
Join Date: Jul 2008
Location: East Lansing, MI, USA
If you can get adapters shipped from Europe, the switch would be easy.
I didn't say cheap and easy. ;-)
If you don't mind some metal work and wiring changes, you can install T5 sockets and use T5 bulbs or lamps, but you will be getting the equivalent of over driven T5NO, not T5HO output.
There are quite a few different ballast types so instant start, rapid start, and programed start may cause some issues, but it will work.
Another option that might be easier, is to install an additional ballast, do a bit of rewiring, and over drive the existing T8 lamps.