Hey Guys, I have 2 Koralia 3's in my tank to create more water flow. What is the best place to put them. Where I have them now, it is causing the sand to move away in certain areas of my tank. Is it because I just dont have much floor cover in the tank. I have them on the sides, about mididdle. One faces forward, the other face towards the back. I have them kinda angled up so that they arent blowing into the sand, yet it moves it anyway. Any help would be great.