I have two smoothhounds that are about 12 inches long each. I have them in a custom tank that is 7' long 30 inches wide and 18 inches tall(200 gallons). They are fairly active, but do rest on the bottom occasionally. This tank is no way large enough and I kind of stubbled into a rescue role with this sharks. Hence the construction of the pond. The pond will be 10 feet long by 5 feet wide and 36 inches deep. I pretty much have all of the expensive parts(skimmer), I'm making the room look pretty(I'm married) first and the actual pond construction could start this weekend. I don't anticipate the construction of the pond to take more than a couple of days. I've been taking some pictures along the way and will post as I get further along.