I want to buy a Fluval 404. I was looking at it in the store and the tube that the water get sucked up into looks kinda big. My turtles are still under 2 inches and I was wondering if they could get hurt by the filter. I want to buy them a 50 gal tank now instead of just wasting money on bigger tanks every year. They can never be in too much water right? It's a lot of money to be spending on something I'm not sure about yet. Thanks!