Is it better to have fast or slow water movement through the back of a Biocube 29 for optimal filtration. Going to be using an InTank Mediabasket with floss/purigen/chemipure. I have a MJ1200 that I could replace the stock return pump with, but am starting to think maybe the slower stock return pump would be beneficial because the media would have more contact with the water. I could place the MJ1200 in the tank for water movement there. Thoughts?