GST on Reactor machine used in Hand Pump for water disinfection

In re Taraltec solutions private limited (GST AAR Maharashtra) GST Rate Applicability on reactor machine which is used in Hand Pump for water disinfection Reactor, in the case of the applicant is nothing but a filtering or purifying machinery/apparatus for liquids. Apparatus used for filtering or purifying water falls under Heading 8421 21 attracting 9% CGST and SGST each. The Reactor is neither an Ion exchanger plant or apparatus, Household type filter and therefore would fall under the others category i.e. 8421 21 90,thus attracting 9% CGST and SGST each.  Classification of goods (i.e React...