Algae Eaters Required

I guess the goldfish bowl needs a bit of a clean! The water's fine (honest) 'cos there's a mini eco-system doing the business but the algae has just got a bit out of control. If I stopped feeding them they'd quickly start grazing that down but I think they prefer their processed food. They're off to Uncle Jack's soon for a wee holiday though, so it'll be change of bowl, new water, new view. Just like us!