The Pond has its own filtration house in which we have One Prime Vortex and 8 Biological Vortex Units all being 6ft tall x 54" diameter and each holds approximately 400 gallons The rockwork is 'Yorkshire Lime Stone' and we actually used over 75 ton of it to construct our waterfalls and complete the landscaping Naturally there does have to be an element of trust afforded to us by our customers and we hope that trust will be forthcoming ..