Hello let me say I've done a bit of reading here first and thank you for the wealth of knowledge . I'm Constructing a pond with the sole purpose of giving my two black Labs a place to swim a tiny bit. I've dug the pond its roughly 13x15 with a couple of small ledges and plan on a waterfall its got a berm roughly 3/4ths of the way around it. I'm purchasing the liner in a couple of days it will be a EPDM 45ml Carlise. I'm still researching filtration /pumps ect and am planning on asking opinions in the other section . I have also purchased quite a bit of landscape rocks mostly flat sandstone with a few boulders and other rocks the plan is to construct the waterfalls with the flat rock as well as line the bottom of the pond with the flat rock.