If you have the money to pay a guy to take care of the pond and clean it ,then rocks look nice .I saw a the pond store here where they where doing a show on how they clean ponds and gosh the way they do it looks scarey to me ,but guessing since they are pro's they know what they are doing .They do charge a lot for there service though .If you get a yearly contract it is just over 800 dollars for them to come out anytime there is a problem and do 2 cleanouts a year .Seems like a lot of money to me .Interesting to watch how they isolate the fish to one side of the pond and clean it out .Seems the fish are not stressed at all by the way they do it .They use a high powered vac. that sucks the water out and filters it and just lets it go right back into the pond .Neat thing to watch .Not sure what else they may be sucking out that may be living .To put in a new pond with all the bells it is over 6 thousand dollars waterfall filters,liner ,fish ,plumbing,media,skimmer ,bottom drain and rocks .I guess not bad as you can watch them work .Waterfall is 8 ft. long and pond is 20x20 .