I am at the point on what type/size of skippy filter needed for my pond. I am new to all this so please be patient with me. According to the dimensions on the attachment what would you guys recommend. I am really leaning towards the 55 gal filter or the 70 gal skippy I have seen here mentioned. My question is would the 55 gal be enough to filter such volume or do I need to go with a bigger size taking into consideration the tubing length, head, etc. You guys can advise me better since you guys are the experts. Thanks