I have discussed the photo above with Pacific Coast Imports the supplier of Gen X water pumps. The following is their response.
"The stainless steel metal showing on the back of the pump is for the thermal overload protection and is an improvement that has been made in the quality of the design. The rust looking material on the stainless steel is metal ions from your aquarium water that has attracted to the stainless steel. It can be removed with some steel wool .It will look shinny underneath the metal ions that have accumulated on it."
Stephen A. Weeks
Pacific Coast Imports Inc.
d4a2n0k Please come see me and we will take care of this.
Thank you
Tony Concialdi
Reef Exotics
www.acropora.net