I have a mag 9.5 on my 75 gallon and it does a great job. Some people say they get hot and cause your system temperature to raise. Since its what came with my system when I bought it used I have stayed with it for now. The mag is completely submersible but realize that its return with no head loss is 950 gph and it calculates out in my tank to be about 800 gph at the outlet which is why I placed a t splice in mine and put the overflow back into my refugium. Since you have a wet dry I don't know what your capabilities are going to be to do the same thing as I'm pretty sure your pump will also over drive your overflow.