Which still is a lot of oney for ONE fake rock... I filled my complete tank with river rock for that money. I can't see any significant pros to justify the cost. They are lightweigth, but weight is not really an issue. Unless you rearange your tank often. They provide caves, but some have only one hole so a possible trap for stagnent water. The breeding cave souds great, but I guess fish like another way out just in case a predator waits before the entrance. The video looks stunning, not doubt about that.gheitman said:until you think that it is about $4.00 each.