I've got 40kg of Ocean Rock in my tank now. Its looking quite good. Need to take some photo's with a decent camera as my camera phone gives the impression that the water isn't as clear as it is!
Its not an off the shelf tank. It was made by a company somewhere in Chorley. My mate bought it new about a year ago and used it for marine for about 4 months then decided to go back to freshwater but he didn't ever actually put anything in it. So I offered to buy it off him.
Its about 200 litres (UK). Its over 3 foot across the front. With it being quite tall I've been able to stack the rocks higher so that they do make use of the height