I am trying to find a nano skimmer for a 20G for a friend. The best one I can seem to find in his budget is the aqua one 40 nano skimmer. However this says it’s only rated up to 10 Gallon tanks! He is also running a wave maker, HOB filter and a UV steriliser so do you think it will be okay? If not do you have any alternative ideas? Have to be under £60 & available in for the UK