WOW - I am so glad that I found a Forum dedicated to the RSM. I have been trying to decide if I could handle something as large as a 55 gallon tank, and did not really want to go that large. I was considering the RSM 130D, but spent a few days reading on other Forums and couldn't find anyone who already owned one. I will now be ordering my RSM 130D as soon as possible. I know I have a place where other users can offer me guidance and advice.