Is this real time, or slightly sped up?, l once ran these in the house, on 20 watt tube chokes, (as a bit of an experiment) , however, without the proper gear, and our crappy, fluctuating power supply, they started to suffer starting problems 4 months in , this one looks well in here though.

Sped up. Takes about 40 seconds. They are supposed to be driven at around 80v. I'm not sure what ballasted UK mains would do but from your experience it don't sound too good!

This all started a while back, and we wanted to try a 20 watt one on a magnetic gear set up out of interest, James reckoned a two foot tube choke would be a good choice. I installed 2 in our house, one on the landing, and one in the hallway. For the first few months they both started and ran perfectly, then the one in the hallway didn't fire up one night, and a few weeks later the one on the landing started to play up!, the proper electronic gear for them at the time was quite expensive, but it would have made a more viable solution running them on tube chokes, sadly it wasn't to be though

Shame. It's always good when you can swap gear between different lamps. You can get little all-in-one electronic ballast/transformer/ignitor box things off of ebay for about 6 quid for 20w MH's