Hello all. I am setting up a 20g long. My main focus is a thick carpet of DHG my secondary focus will be glass shrimp. My question today is will the 402b be to much flow for such a small tank? The 402b has lower wattage than other models and a uv light its rated at 264g/hour but with research i guess that will be cut down significantly with media. Please share your thoughts and experience, thanks much.