In reply to Andy Morley:
he's already using all the rainwater for watering a large, terraced, garden. After a quick look at what people have mentioned it might be a whole lot simpler and involve less chemical usage to suggest to him that he takes some of the greywater from their bathroom and filters it for supplementing the garden water during times of less rain.... don't know if I could enjoy their home grown veggies quite the same though
Any ideas are good as the research is part of what keeps him busy. Pretty much anything that keeps him away from his woodturning for a while is good. Not only can the whole family no longer find a use for any bowls but I think we have all saturated any and all regifting opportunities with friends .....