Hello everyone. It's been quite a long while since I've been on here. I've been out of the hobby for about a year or two for various reasons, and I've decide to get back in again. I've sold all of my aquariums (yes including my 250g ) accept for two 10g's and a 1/2g hex. The hex is occupied for a FW guppy for my son, leaving the two 10g's. So to save money I'm starting my project in one of them. I've always been fascinated by tidal ecosystems and wanted to create one (as closely as possible) for the longest time. I've been looking up ideas on how to build DIY rock formations/walls, surge/switching current devices, and filtration systems. My plan is to make a rock wall with bulges, shelfs, and caves, along all three sides. Along the middle of the back wall I will place the pumps and filtration system. The jets will be placed in each back corner aimed at their opposing corners across the tank. The center will be open with a bare sand bed. Though I may place a few LR rubble for debris along the sand bed. Since I'm doing everything internally I'm not going to worry about rising and falling tides with a reservoir or anything like that. I'm just going for the strong shifting currents at this point being that it's my first tidal tank. I'm using a 3/4" SCWD and 900 Maxijet for circulation and switching current. The rock that I want to use (as I have not yet purchased any rock) is referred to as "dragonstone" by the person who sells it. The idea that I'm going with is kind of a volcanic/alien world here. I think I can pull of a really creative and artistic look with the lighting that I have and this rock. My concerns are being that this is a small (10g) tank, with a strong alternating current, and the walls are covered with volcanic rock, would a setup like this be octo friendly? I'm pretty sure that common sense dictates no, but I thought I'd run it past the rest of you who are more knowledgeable and more experienced than I. Though let me say that this is not a temporary octo tank. I am building this with the intent of a reef/invert tank. But I was thinking I could use it as a grow out tank for any future octopus. Questions, comments, concerns,..improvements?