Off course you’re not going to be fired, I also questioned it. I normally keep blackwater fish in pure RO water, with leaves and peat added. When I didn’t use peat or leaves, the fish seemed to run out of salts and minerals. They didn’t colour up and looked sick. This quickly disappeared when I added oak leaves. It also disappeared a bit when I added plant nutrition, but not as good as humic, and it also raised the pH.
In tap water though, they do fine without humic or anything. But since they don’t breed in tap water I recommend using RO with humic acids. So if you want to keep them alive until you have a sufficient breeding tank I recommend using tap water, but as soon as possible get them an acidic blackwater tank for breeding.
This goes up for all fish I tried it with, including Apistogramma, Dicrossus(these did a lot better though), Betta, Pelvicachromis(this was by accident, didn’t intend to try them and they really didn’t like it!!) and Parosphromenus.