hi Jacintha,ll
feel free to contact us also, but when you say 'dont do so well' do you mean there's not a lot of juice extracted or that the machine isn't working well? It will also depend on the produce and how ripe it is, older produce (carrots, cucumber, apples etc) will not extract as much juice. Also you may need to give the parts a quick clean before changing nozzles for other produce etc as celery is stringy and can block things up a bit.
Please get hold of us if you're still having trouble, happy to walk you through it
cheers Carrie