I have a 20 gallon long that I want to make into a refugium to grow Calerpa under my 150 gallon reef. I have a hong on the back overflow and a return pump already. I also have all the plexiglass I need. I had a design but then saw somewhere that you needed something to eliminate the bubbles for the return. if my first design would work it would be easier but if I have to go with the second I will. I am looking for some guidance. If I need any holes drilled in my plexiglass panels let me know. would this be too much flow or does it really matter since I am just trying to grow Calerpa (and any other algae I can get my hands on) I would love some Ideas because I have all the supplies I need (Including a plant grow light) and would like to get started right away.