Just dismantled the quarantine /grow on pond to enlarge it ....using the the existing slab i dug out b/drain and using hollow blocks 4 courses high 3 m x 1.8 m......and a 1.2m x 60 window .My main pond and indoor pond are both run on drum to k1 moving bed........but i get fed up topping them up all the time as i cannot get mains to them .So i am going back to the old fashioned way using a big cloverleaf P1020157.jpg