Lots of info on the forums on holding tank replacement. I have replaced mine with the Triple M one. Job was very easy and was done just in time. Corners on the aluminum one were breaking down. Acquired this drawing of the original aluminum tank installed by Hunter and thought it may be of use to some of you. The Triple M tank fit very well, could actually be a little deeper to hold more but probably not worth the effort to have Triple M change the design. The new tank appears very well made and service from Triple M was excellent.