Thanks everyone, sounds like a good option is to keep an eye on him and check he's looking healthy before we go and let him then go without for a bit...
I received a Biorb tank for Christmas (small 15L one) which now has a single betta in it who currently seems happy. We're feeding him tiny pellets a couple of times a day as directed.
The problem is we'll soon be away for a holiday for around 10 days. I've read it's fine to leave them for a long...