240 has been ignored but now trying to get it back in shape and better. Rockwork will now be two floating islands on PVC platforms for more flow around them. I have used a pair of Tunze 6100s for years and love them. The new return pump is a Dart that I am considering using two Wavy Sea devices-one on each return behind the islands. This should create random flow into the rockwork and decrease detritus build up combined with the Tunze. Has anyone had experience with Wavy Seas? The idea sounds great and they handle more flow than the Sea Swirl. I will not have a closed loop or I might consider OM, so Wavy Sea is one option. Any thoughts would be appreciated.