Ricky, I just read the Practical Fishkeeping article. You were right. Those LED
tube require a magnetic ballast. That is a step backwards
in time. Initially I did not think that you knew what you were talking about. Nobody buys magnetic ballasts anymore! The Electronic Ballasts replaced the old magnetic ballasts years ago. To make matters worse, the magnetic ballasts require a starter. You don't want that. What you can do is something like this: G13 4FT 20W 3000K 4000K 6500K CLR STR MLK T8 Fluorescent Replacement LED Tube | eBay
tubes appear to be 4 feet long and they require NO ballast. I did see 6500K tubes with three different diffusers: clear, milky, and striped. Keep looking around the UK for LED
tubes that are 6500K if these are too expensive.