I have just been pointed at the fairly new " Graf, water treatment plants " " one2clean" and as this is something I will need a decision on this coming spring I was wondering if anyone else has considered one, had one or just has any views on its merits or not.   https://www.drainagesuperstore.co.uk/product/domestic-sewage-treatment-plant-5-person-3750l-graf-one2clean.html