Just remember that the polyethelene group of plastics (HDPE, LDPE) are so chemically resistant that they are virtually impossible to solvent weld (glue). This material is commonly used in labs and research facilities where corrosive materials may be used. Connections may be made mechanically by bulkhead fittings or by heat fusion only. Strength wise for all practical purposes they are the same. The polyethelene may be a bit more brittle. If you were looking for a replacement for a fresh water tank I would suggest the polyethelene, otherwise use the ABS.
Hope is not a plan.