Hi tanks. Had mine on for about 1.5 years now. Love it. I wouldn't worry to much about flow. I have mine on a 1500 litre tank fed directly from the main return. Amazed at what it filters out of the water. 2 things in my opinion to look out for. If you have any lights in your sump for algae try and cover the side of the Matt . Long term it gets full of coralline and algae. Second thing is if you are struggling on flow . Lift up the float switch a little (you can get quite a bit of movement on this). This will help you when setting your flow. Their is a picture showing my set up on my thread , but I do not know how to add a link to it . Sorry . Maybe you can have a look by my user name.