yes, my alum tank has no additives put back in.. Altum come from water that is very low pH read below 6 usually in the 5.5 or lower range.. their wateis high in tannins low in dissolved solids(blackwater)
they are born in low tds blackwater, transported in the same water.. often kept in conditioned water until sold.. they often come in already suffering.. so it is usual to put them back in low pH low tds water that has had peat filtration added pH is below 6 .. now with this in mind bacteria that consume ammonia is nearly non existant(however, there is some reseach looking into bacteria that live in these waters that actually handle the nitrification issues) but that said.. ammonia NH3 is easily converted to NH4 in the acidic water soit isn't a problem, bacteria that affect our normal fish are also less prolific in the low pH acidic water so there are fewer bacteria issues as a result.. the fish can then be conditioned slowly to our std tap.. close eye must be kept tho as you will need to adjust for nitrification as well as other pH related issues.. my Altum have never been fully acclimated to tap so I continue to use
RO have done so for 4-5 years now..
BTW Altum are the giants of the freshwater Angel world I have some that with fins are easily 11-12" tall