So, I have an IM 20 and last night my yasha goby (as best as I can tell) swam through the grates into the rear chamber, jumped out of that chamber and into the chamber where the pump is located. After searching for him all day I noticed him swimming in the rear chamber. The problem is there is blank space on the underside of the chambers adjacent to the chamber where the pump is. Because the width of the rear chambers is only about three inches it is impossible to get anything down and under the adjacent chambers. The second the yasha is spooked he hides out under the chambers and I am at a loss as to how to get him out. Hopefully before he figures out how to escape again! Any ideas or thoughts or anything is much appreciated!