I had my 75 gallon tank drilled at a local pet store and when he drilled I asked what to do and he said just put a 90 on it pointing up so I did this and it is extremely loud. This is the first tank that I am setting up with a sump but it is way to noisy, sounds like someone flushing a toilet and gurgling at the same time. They drilled the hole a few inches from the top on the back. I have spent the last couple hrs looking online and I am not finding any pic's that can help me out. Any ideas would be appreciated.