Thanks! So I shot myself in the foot again. I got gravel for the 400 because I didn't want to take the chance of not liking sand, and just got some sand for the 125 to give it a try, and love it. It looks so clean. Maybe when I get another few smaller tanks I will scoop the gravel out for them and get sand for the 400. Tried out my invention of super duper speedy water change setup tonight too. I put a T in the return line with ball valves at each end. One end goes to the tank, and the other goes outside through the house. I just close the one to the tank, open the one outside, and turn the pump on again and empty out the sump. I just have to get rolling on the water lines going to the tank area and I'll be all set. I'll get a water temp mixer too so I can just turn the water on and fill up the sump with warm water. I'm loving it.