gULP installed as a gravity fed system
In the picture above the settlement chamber water level is at the same level as the Koi pond - obviously. The gULPs located to the left of the picture also have the water level in these at the same level as the Koi pond. in other words the entire filter system is filled by gravity to the same level as the Koi pond.
Water discharges again by gravity into a pump chamber from where the pumps pick up the water and return it back to the pond.
Some care needs to be taken to ensure that you get your levels and flowrates corrects. gULP is designed to run optimally at 10kl/hr but can run at a maximum rate of 12kl/hr if necessary. gULP is forgiving in terms of levels at the filter has been designed to keep a good level of water above the top 110mm exit on the filter.